My collars started doing the same thing the last
few months after setting up a while. No birdseye involved.
Garmin made me up date the collars

Then had to do a factory reset..

Warning I had three collars that would not turn back on and had to buy 3 new collars from Garmin. (sounds like you are under warrenty)

It did fix my problems on all other collars and I
have had zero problems last two weeks.

Call Garmin if needed , they will walk you thru it