This might sounds weird but I thought I share it as it might helps Garmin in debug.
So I have kept my FR945 on SW 2.80 long ago because that proven to be stable for me and all newer releases had serious bugs.
In the recent weeks I have experienced slow I mean very slow GPS acquisition. Once it wasn't completing during a whole run (30 mins!) - never happened before. So I thought ok, maybe satellite data changes sometime and I need to update. So I thought I will update the GPS only. Why not, a simple GPS update should not be risky.
GPS updated from 2.50 to 2.90.
Then after the very first run my watch has been rebooted when I chosen "save". Activity has been saved though!
I did not had any reboot on this watch ever before - it is about a year old.
Full version stack: SW 2.80 GPS 2.90 WiFi 2.60 CIQ 3.1.1 BMX 0.4.8 WHR 20.04.40 BT 3.60 SH 2.50
No new CIQ field/widget/anything installation, no any other setup, was using it as usual.
It was only the GPS updated before this issue + sure it was rebooted because of that (actually 2x, to make sure).
Yep, GPS acquisition was fast.
Btw, I could not downgrade GPS, the file is disappearing if I put it back to the RemoteSW forlder but downgrade not happens.