My 520 seemed to work fine but for some reason wouldn't connect via bluetooth to the android app. Had to remove it and re-pair for it to work again (and upload a ride). It took some time for some reason to load up the screen in the app for devices though.

My watch (245) seemed to reconnect and synce with no issues or additional steps.

On another forum there is discussions about Garmin on how they handled it and supposedly they paid the ransom (according to the thread topic header)...not a good sign.