Build 2.40 is the latest for the UT800
The 2.50 build mentioned in this thread is for the prior generation of Garmin headlight. The HL 500.
If 2.40 is the latest build for the UT800, why does my Edge 1030+ still continue to say "checking for updates?" I have the same issue with my Garmin Radar. It is running the latest software (according to Garmin Express) but it also says "waiting for update" on my Edge 1030+. The Edge seems unable to confirm that these accessories are already running the latest software.
Same issue here with my UT800. it keeps showing "checking for updates". Did you find out how to sort that out?