diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/xiaomi/activity/XiaomiActivityFileFetcher.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/xiaomi/activity/XiaomiActivityFileFetcher.java
index 57cdea2fa..688391c02 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/xiaomi/activity/XiaomiActivityFileFetcher.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/xiaomi/activity/XiaomiActivityFileFetcher.java
@@ -17,6 +17,8 @@
 package nodomain.freeyourgadget.gadgetbridge.service.devices.xiaomi.activity;
 
 import android.content.Context;
+import android.os.Handler;
+import android.os.Looper;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -48,84 +50,120 @@ public class XiaomiActivityFileFetcher {
     private ByteArrayOutputStream mBuffer = new ByteArrayOutputStream();
     private boolean isFetching = false;
 
+    private final Handler timeoutHandler = new Handler(Looper.getMainLooper());
+
     public XiaomiActivityFileFetcher(final XiaomiHealthService healthService) {
         this.mHealthService = healthService;
     }
 
+    public void dispose() {
+        clearTimeout();
+    }
+
+    private void clearTimeout() {
+        this.timeoutHandler.removeCallbacksAndMessages(null);
+    }
+
+    private void setTimeout() {
+        // #4305 - Set the timeout in case the watch does not send the file
+        this.timeoutHandler.postDelayed(() -> {
+            LOG.warn("Timed out waiting for activity file with {} bytes in the buffer", mBuffer.size());
+            triggerNextFetch();
+        }, 5000L);
+    }
+
     public void addChunk(final byte[] chunk) {
+        clearTimeout();
+
         final int total = BLETypeConversions.toUint16(chunk, 0);
         final int num = BLETypeConversions.toUint16(chunk, 2);
 
+        if (num == 1) {
+            // reset buffer
+            mBuffer = new ByteArrayOutputStream();
+        }
+
         LOG.debug("Got activity chunk {}/{}", num, total);
 
         mBuffer.write(chunk, 4, chunk.length - 4);
 
-        if (num == total) {
-            final byte[] data = mBuffer.toByteArray();
-            mBuffer = new ByteArrayOutputStream();
-
-            if (data.length < 13) {
-                LOG.warn("Activity data length of {} is too short", data.length);
-                // FIXME this may mess up the order.. maybe we should just abort
-                triggerNextFetch();
-                return;
-            }
-
-            final int arrCrc32 = CheckSums.getCRC32(data, 0, data.length - 4);
-            final int expectedCrc32 = BLETypeConversions.toUint32(data, data.length - 4);
-
-            if (arrCrc32 != expectedCrc32) {
-                LOG.warn(
-                        "Invalid activity data checksum: got {}, expected {}",
-                        String.format("%08X", arrCrc32),
-                        String.format("%08X", expectedCrc32)
-                );
-                // FIXME this may mess up the order.. maybe we should just abort
-                triggerNextFetch();
-                return;
-            }
-
-            if (data[7] != 0) {
-                LOG.warn(
-                        "Unexpected activity payload byte {} at position 7 - parsing might fail",
-                        String.format("0x%02X", data[7])
-                );
-            }
-
-            final byte[] fileIdBytes = Arrays.copyOfRange(data, 0, 7);
-            final XiaomiActivityFileId fileId = XiaomiActivityFileId.from(fileIdBytes);
-
-            dumpBytesToExternalStorage(fileId, data);
-
-            if (!XiaomiPreferences.keepActivityDataOnDevice(mHealthService.getSupport().getDevice())) {
-                LOG.debug("Acking recorded data {}", fileId);
-                // TODO is this too early?
-                mHealthService.ackRecordedData(fileId);
-            }
-
-            final XiaomiActivityParser activityParser = XiaomiActivityParser.create(fileId);
-            if (activityParser == null) {
-                LOG.warn("Failed to find parser for {}", fileId);
-                triggerNextFetch();
-                return;
-            }
-
-            try {
-                if (activityParser.parse(mHealthService.getSupport(), fileId, data)) {
-                    LOG.info("Successfully parsed {}", fileId);
-                } else {
-                    LOG.warn("Failed to parse {}", fileId);
-                }
-            } catch (final Exception ex) {
-                LOG.error("Exception while parsing {}", fileId, ex);
-            }
-
-            triggerNextFetch();
+        if (num != total) {
+            setTimeout();
+            return;
         }
+
+        final byte[] data = mBuffer.toByteArray();
+        mBuffer = new ByteArrayOutputStream();
+
+        if (data.length < 13) {
+            LOG.warn("Activity data length of {} is too short", data.length);
+            // FIXME this may mess up the order.. maybe we should just abort
+            triggerNextFetch();
+            return;
+        }
+
+        final int arrCrc32 = CheckSums.getCRC32(data, 0, data.length - 4);
+        final int expectedCrc32 = BLETypeConversions.toUint32(data, data.length - 4);
+
+        if (arrCrc32 != expectedCrc32) {
+            LOG.warn(
+                    "Invalid activity data checksum: got {}, expected {}",
+                    String.format("%08X", arrCrc32),
+                    String.format("%08X", expectedCrc32)
+            );
+            // FIXME this may mess up the order.. maybe we should just abort
+            triggerNextFetch();
+            return;
+        }
+
+        if (data[7] != 0) {
+            LOG.warn(
+                    "Unexpected activity payload byte {} at position 7 - parsing might fail",
+                    String.format("0x%02X", data[7])
+            );
+        }
+
+        final byte[] fileIdBytes = Arrays.copyOfRange(data, 0, 7);
+        final XiaomiActivityFileId fileId = XiaomiActivityFileId.from(fileIdBytes);
+
+        dumpBytesToExternalStorage(fileId, data);
+
+        if (!XiaomiPreferences.keepActivityDataOnDevice(mHealthService.getSupport().getDevice())) {
+            LOG.debug("Acking recorded data {}", fileId);
+            // TODO is this too early?
+            mHealthService.ackRecordedData(fileId);
+        }
+
+        final XiaomiActivityParser activityParser = XiaomiActivityParser.create(fileId);
+        if (activityParser == null) {
+            LOG.warn("Failed to find parser for {}", fileId);
+            triggerNextFetch();
+            return;
+        }
+
+        try {
+            if (activityParser.parse(mHealthService.getSupport(), fileId, data)) {
+                LOG.info("Successfully parsed {}", fileId);
+            } else {
+                LOG.warn("Failed to parse {}", fileId);
+            }
+        } catch (final Exception ex) {
+            LOG.error("Exception while parsing {}", fileId, ex);
+        }
+
+        triggerNextFetch();
     }
 
     public void fetch(final List<XiaomiActivityFileId> fileIds) {
-        mFetchQueue.addAll(fileIds);
+        // #4305 - ensure unique files
+        for (final XiaomiActivityFileId fileId : fileIds) {
+            if (!mFetchQueue.contains(fileId)) {
+                mFetchQueue.add(fileId);
+            } else {
+                LOG.warn("Ignoring duplicated file {}", fileId);
+            }
+        }
+
         if (!isFetching) {
             // Currently not fetching anything, fetch the next
             isFetching = true;
@@ -139,6 +177,9 @@ public class XiaomiActivityFileFetcher {
     }
 
     private void triggerNextFetch() {
+        clearTimeout();
+        mBuffer = new ByteArrayOutputStream();
+
         final XiaomiActivityFileId fileId = mFetchQueue.poll();
 
         if (fileId == null) {
@@ -153,6 +194,8 @@ public class XiaomiActivityFileFetcher {
 
         LOG.debug("Triggering next fetch for: {}", fileId);
 
+        setTimeout();
+
         mHealthService.requestRecordedData(fileId);
     }
 
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/xiaomi/services/AbstractXiaomiService.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/xiaomi/services/AbstractXiaomiService.java
index aa800ab77..90f29ad59 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/xiaomi/services/AbstractXiaomiService.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/xiaomi/services/AbstractXiaomiService.java
@@ -42,6 +42,10 @@ public abstract class AbstractXiaomiService {
 
     }
 
+    public void dispose() {
+
+    }
+
     /**
      * Handle a preference change.
      * @param config the preference key
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/xiaomi/services/XiaomiHealthService.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/xiaomi/services/XiaomiHealthService.java
index 558523eed..189da3ce4 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/xiaomi/services/XiaomiHealthService.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/xiaomi/services/XiaomiHealthService.java
@@ -203,6 +203,11 @@ public class XiaomiHealthService extends AbstractXiaomiService {
         getSupport().sendCommand("get vitality score config", COMMAND_TYPE, CMD_CONFIG_VITALITY_SCORE_GET);
     }
 
+    @Override
+    public void dispose() {
+        activityFetcher.dispose();
+    }
+
     @Override
     public boolean onSendConfiguration(final String config, final Prefs prefs) {
         switch (config) {