Problems with GPS lock

If you've done everything recommended on P28 of the user manual then you might have a problematic GPS on your device. As for memory? What 'extras' over and above default do you have loaded? Possible that one of those is leaking memory.

If you have no extras then try power cycling the device, a soft reset, or a hard reset. If you have extras, try removing them all. Then add them back one-by-one to see if you can find the item at fault.

I usually get a lock within 20-30 seconds. I only remember once when it took like 3-4 minutes, but that was in a very narrow canyon-like mountain pass after a break when resuming the activity.
Do you live in a place where GPS is generally weak (tall buildings, trees, mountains etc.)? If not, I would guess some problems with the GPS chip itself. Have you tried a hard-reset?

I have had it a few times now that I couldn't seem to get a lock (the ring stayed orange). At one time I started running anyway but found out afterwards that it didn't record the track until it turned green (and I got the bzzzz). Pace and everything was recorded though, so all in all a bit strange.

Two other times I tried restarting the watch and after the restart I did get the fix pretty much instantly. So not sure what to think of all of this, but restarting the watch might be worth a try next time you have an issue. (It restarts pretty quickly anyway, only downside is loosing the OHR 4-hr history I think)

If you connect the watch to a computer, how much space is it reporting?

if you are using a Mac you may need to empty your Trash folder to clear the files.

Why you could run out of room so early is a bit odd though. But maybe the device is full up and cannot put the EPO.BIN file on there for fast satellite pickup.

Thank you for all your suggestions. I'll do a testrun today and get back to you if I find the reason for the laggy GPS. Concerning the reception - I live in a city but I always got a lock rather quickly although the track is not very precise as long as I'm located between buildings. Maybe a soft reset helps.

This is interesting to me because I had an issue this week as well. I normally get a pretty quick lock and have strong GPS signal everywhere that I do activities. I did a 1-hour "indoor bike" workout session earlier this week and everything worked as it should. I then got off the bike, put my watch on(it was strapped to the handlebars for the ride), and went for a run. I selected run and the GPS ring immediately was red(nothing unusual about that), but then it stayed red for at least 5 minutes. I started to think that maybe I was going to have to restart the watch or try something else when it finally turned orange. Then it stayed orange for another two minutes or so before finally going green. I went and did my run and it tracked everything fine. It was the only time I have ever seen it take that long to get a GPS lock, including travelling to another state and then trying to start an activity. I had just done an activity the day before that had a GPS signal the whole time and it had locked on within about 30 sec.

I have no extra widgets or apps.

Sorry for my belated response but I did not have the chance to go for a run in quite a while to test your suggestions. A simple restart seemed to fix the problem.

When I tried to connect to watch to my PC via USB I got an error message (something like "device not recognized") and in Garmin Express the 935 was "not connected". After a restart I did not get this message and the watch synced as expected. GPS lock is also working again. On my last run it did last about 5min until I got a lock but that was between taller buildings so that could have been the problem. I also noticed that the red circle progressed more quickly when I was standing still. Strangely the circle skipped from orange to red 2 or 3 times until i got a lock, no idea if that's normal.

Having now got my 935 I too am seeing extended times getting GPS lock even at the same location. A restart does seem to fix it but not sure if that is because of the restart or because it was about to get a lock before I power cycled the watch. I've added nothing extra to my Garmin either. I have said this in other posts but, whereas my 920 will get a GPS fix indoors pretty quickly, the 935 takes much longer. Clearly there's a significant difference in the GPS between the two devices. I started typing this in with both seeking GPS. The 920 got its GPS quite quickly; the 935 is still looking.

I have a similar experience getting a GPS lock indoors. With my old watch I had a lock within a minute, with the 935 it pretty much stays a small red circle segment for minutes. However outdoors sometimes I get a lock within 10 to 20 seconds. Still it's a bit frustrating to lose a part of your run waiting to get GPS reception.

Switch it on when you arrive, surely you don't get ready to run in less than 20 seconds??