After Successful Pairing, Pairing Mode Keeps Re-Appearing

I upgraded to the Fenix 6 last month and gave my wife my 5 Plus. I completely wiped the device, and then I walked her through the pairing process on her Android phone. All seemed good, as she is able to sync activities to Garmin Connect.

However, since then, on at least a weekly basis the watch has triggered pairing mode at seemingly random times. What I'm seeing is those six digits with a rotating border appear and if I back out, it just reappears within a few seconds. Has anyone seen this before? In two years of using this watch daily this is the first time I've encountered this.