- The following checklist attempts to cover all possible reasons of failing synchronization. If you encounter connectivity problems, please read it carefully and eliminate one point after the other, not skipping any, even if you think it cannot help. All of the points are listed because they did help other users in the past cases. More tips will be added, if found useful.
Most common way people use for resolving this kind of problems, is uninstalling and reinstalling the application. Sometimes it can help, but often only temporarily, because you usually did not really resolve the true problem. So, although it is also a way how you can try fixing the issue, let us focusing also on other alternatives, and trying to find and eliminate the problem.
- First of all check out whether the latest version of software (firmware) is installed on your watch. If you can successfully connect to the watch with Garmin Express via the USB cable, try whether syncing works at least over the cable, and check also for the latest software update with it. Otherwise, look up the watch software version directly on the device (typically: long-press the Menu button » Settings » About, but it may depend on the watch model), and verify with the support page for your model on Garmin's website whether there is an update available.
- In the Privacy Settings of your Garmin Connect Web, make sure the options Storage & Processing and Device Upload are enabled
- In Device Settings in Garmin Connect Web, verify that the option Activity Tracking is enabled, and also verify whether the option Preferred Activity Tracker is checked in the Device Settings » Activity Tracking.
- Check out the Sync Audit on the phone app, and search for any error messages of warnings. You can browse through the history of the audits on the screen GC Mobile Menu » Settings » Device Sync Audit (note the navigation buttons at the bottom of the screen to review also previous reports, and not only the last one)
- One of relatively frequent reasons for a stalled syncing is a corrupt FIT file, mostly a file of a recent Activity. Open the storage of your Garmin device over the USB cable in a file manager (such as File Explorer in Windows or File Finder in MacOS), and download the un-synced files from the folder //GARMIN/Activity (the date is used for the file names). Try importing those files by dropping them onto the Import page of Garmin Connect Web. In case some of the files triggers errors during the import, delete it from the device, and try repairing and reimporting the file using the Section Remover of FIT File Tools (without removing anything), or consult the thread How to repair a .fit file?
- In some cases, especially with older devices, full storage may cause faulty FIT files and/or sync problems. Clean up regularly the folder /GARMIN/Activity, making sufficient room for new activities. You can also remove unneeded workouts (//GARMIN/Workouts/), courses (//GARMIN/Courses/), and language text files (//GARMIN/TEXT/)
- If the sync seems to be working OK (the circle around the watch symbol closes and the green do appears), but data like heart rate, steps, or activities does not appear on the phone,
then your device might be associated with multiple accounts. It frequently happens for example when you reinstall the application, and inadvertently sign up a new account instead of signing into the original one. Follow the instructions from the support document Data is Missing from My Garmin Account After Syncing to resolve the issue.
You should also try turning off completely both your phone and the watch, waiting a moment, and then turning them back on again. Make sure Bluetooth is on, on both sides.
When you go to the Bluetooth details on the phone (swipe down the top and long-tap the BT symbol), is your watch visible? If not, tap Scan up right. If yes, then in wich section? Available or Paired? If it is in the Available section, follow the installation instructions from you user manual and pair the devices.
- Try disconnecting all other BT active devices, such as headphones, etc.
- If the Garmin device is already paired with another phone (or a tablet, pc, …), remove the pairing.
- Check the menu on the BT screen (on the phone), check the Advanced options, and verify all parameters. On some phones there is an option for clearing the Bluetooth cache. If you find it, use it. If you don't, google it up for your phone model, or use the search function on the Android settings screen.
- Try removing the pairing of the watch from phone's BT devices, and re-pairing it from the phone's BT page (unlike what Garmin's User Manual suggests). If it does not help, remove the pairing again and try initializing the pairing from the watch, just like the User Manual tells. Sounds a bit foolish, but there are many users whom it helped.
- Verify all application permissions in Android Settings » Apps » Connect » Permissions. Check also other sections of the application page in the system settings. The manufacturer of the phone may have added additional parameters. Check all for any susceptible limitations. The Permissions are also accessible from Garmin Connect menu » Settings » Phone Permissions, they should be all turned on
- Try some troubleshooting guides from Garmin Support:
- Check the following troubleshooting guide for HUAWEI (should work for Honor and other clones too). It may apply to your phone perhaps too:
- Another tip for HUAWEI, although for notifications, may perhaps help for certain phones and syncing too:
- And yet more tips for HUAWEI owners: https://thedroidguy.com/fix-huawei-p30-bluetooth-connection-problems-bluetooth-not-working-1104602
- Another HUAWEI owner reports that disabled GPS location service caused troubles with the GC synchronization
- If you skipped the previous points, thinking it did not concern you, check out (on your phone) battery saving parameters, mobile data permissions or saving settings, and lock screen settings - all of them can hinder the communication in some cases (for example disabling the Bluetooth communication at low power, blocking web access when on mobile data, blocking the Garmin Connect background process when the screen is locked,...).
- On some phones (namely reported on several SAMSUNG models), you may need to reset the network settings, typically under Settings » General management » Reset » Reset network settings. Please note you'll loose all network settings for wi-fi and Bluetooth a will have to re-do them. (source)
- Samsung Galaxy S21 / S201 Ultra phone owners report a lot of problems with BT disconnections in general (not only with Garmin products). The phones seem to suffer from conflicts between the WiFi and BT. Try turning the phone's WiFi off to see whether it is your case too. If it helps, then try using a 5GHz WiFi instead of 2.4 GHz. Report the issue to the Samsung Support. (source 1, source 2)
- App Overlays (i.e. Skype, FB Messenger, WhatsApp, etc. use them) may pose a problem on some models of phones, as reported in this thread. Read the thread if you do not know what App Overlays are, or when you want to learn how to disable them.
- Check the changelog of the last OS update of your phone, or contact their support to find out which of the changes of their software could have led to this outcome.
- If nothing helps and you know the previous version of Garmin Connect Mobile worked all right, consider installing an older version from an APK archive. There are several unofficial APK archives available on the web (for example here). Use on own risk - there is no guarantee from Google or from Garmin that those files were not modified by a 3rd party (though I have only positive experience with the mentioned website)