Etrex SE/Solar fails to save track history in cold weather (835)

[gps_techie]

Tracking every second for ~1 hour, there we still few MB left (more than enough). After downloading all tracks to PC and deleting them on eTrex SE/SOLAR, bug has not repeated since.
Reason for this is unclear at this point, may not be temp related.

[GPSrChive]

Perhaps an issue writing to memory when available space is below an unknown level?

[gps_techie]

I cleared all activity memory and eTrex SOLAR failed one more time, but it's very random & rare occurrence. Garmin suggested completely reseting device - after doing this, I have not experienced any issues so far.
Activity record is somehow (unclear how) corrupted which then cannot be saved (but is still hides in memory) which sometimes interferes with other track saving.

If your eTrex SE/SOLAR experiences this, delete "activities" & "GPX" folders (folders, not files) and do a full factory reset with buttons.

[gps_techie]

The same bug happened again on SE & SOLAR (FW 5.01). Low temperature is not a factor. Debug info is available.

Bug is rare, but happens almost at the same time on both devices (SE & SOLAR) with similar settings. Thus I can only speculate that bug has something to do with settings (every second tracking, always tracking, auto daily saving) and device usage (device is turn on to get GPS fix, then data is reset, trip, data is saved). Maybe multiple resets in a row screw up track history (when GPS fix is/isn't available)?