Hi, I recently ran a fairly long ultramarathon, FR955 on 12.27, had the race course loaded. At a later stage it looks like GPS started malfunctioning, started to get coarse position updates, distance was updating but ClimbPro was not and the next waypoint list stopped showing distances. Tried to switch GPS mode to autoselect, helped for a bit, then it lost it again. Stopped recording, restarted the watch, resumed recording (which crashed my CIQ fields...), got a fresh position and then lost it again. Did it few more times but no luck, eventually I reached an aid station stopped few minutes, plugged the watch in while taking a break (had cable and a power bank, at that point it was at roughly 30% battery I think), from that point it started working normally again until the finish.
Now I'm thinking, is it possible that the watch switched to ultratrack automatically to save battery to finish the course? Don't think there's such option on the FR955 but maybe the code is there.
One of the CIQ data field I'm using is logging the GPS quality level (that is currentLocationAccuracy from Toybox.Activity.Info) and what I noticed in the recorded FIT file is that there's many data points where currentLocationAccuracy is QUALITY_GOOD (4) but the position_lat and position_long is reported as invalid, which does not sound quite right.