I suggest trying all of the following to see if anything can help resolve this issue. Of course, if any one item resolves it, you can skip the others:
- Forget all pairings: On your iPhone, go to Settings → Bluetooth, tap the ⓘ next to the Edge 840 (if it’s listed), and choose Forget This Device. Do the same on the Garmin (Menu → Sensors → Phone → Forget Phone).
- Reset Garmin Bluetooth: Power off the Edge, then hold the bottom right button while powering it back on until you see a “Clearing Pairings” message.
- Re-pair cleanly: Reopen the Garmin Connect app, make sure Bluetooth is enabled on the iPhone, and add the device again through the app (not through iOS Settings).
- Manually reset trust settings: On your Mac, open System Settings → Privacy & Security → Location Services.
- Scroll down and toggle Location Services off, wait a few seconds, and then turn it back on.
- Then go to System Settings → General → Privacy & Security → Bluetooth, and remove the Garmin Connect app if it appears listed, then re-grant permission the next time you open the app.
- Restart both Mac and Garmin before trying the pairing again in Garmin Express or Garmin Connect.
- Firmware check: Open Garmin Express and update the Edge’s firmware if prompted — Garmin’s last updates addressed USB enumeration issues with recent macOS builds.
If, after all that, Bluetooth still refuses to pair, temporarily disable Bluetooth LE Privacy in iOS (Settings → Privacy → Bluetooth) and retry. A few users have also reported success toggling Airplane Mode on the Garmin for 10 seconds before retrying the connection.
Last, but not least, there is a bit of a "brute force" method you can consider trying ...
- Open Finder → Go → Go to Folder, and enter: ~/Library/Preferences/
- Locate and delete these two files if present:
- com.apple.Bluetooth.plist
- com.apple.Bluetooth.plist.lockfile
- Then, restart your Mac. macOS will rebuild those files fresh on reboot. This clears all pairings and forces the Bluetooth hardware to reinitialize — the functional equivalent of the old “Reset the Bluetooth Module.”
