Garmin Fenix 5 - Garmin Express v5.3.1 got update some time ago, so check yours in "about" menu and force it to update. CHANGELOGS: Garmin Express v5.3.1 for the PC - This
Garmin Express 7.12.1 - Manage your Garmin devices
Garmin Express Download For Windows | Express Updates | Not Syncing
Garmin Express not finding device, searching, or says its incompatible? - MyHealthyApple