Forerunner 735XT not picking GPS signal, GPS not working

I've been using a FR735XT for over 3 years, and never had any issues with GPS reception. Try rebooting the watch. If this does not help, try hard reset. And if hard reset does not help either, then contact garmin support, as it's possible that your watch is defective.

Updated to 9.80 a few weeks ago and have been having bluetooth connectivity even after a factory reset. Wondering if anyone else is?

Wanted to downgrade to 9.70 does anyone have the .gcd file for this?

Were u able to fix it I can't get gps on mine a disaster I only have since March and no response from Garmin 

I have been using FR735xt more than 2 years. Till last April, my watch was able to get 5 bar GPS in just few minutes and tracking was excellent. When I've started running again on June, after quarantine was lifted, I couldn't able get GPS. I have tried everything. GPS only, GPS and Glonass, deleting apps and widgets, soft reset, hard reset, latest updates, virus scan, storage bad sector check nothing worked. Once I left the watch on the balcony 2 hours and still no GPS. 

However I keep trying, leaving the watch on the run mode on the balcony or whenever I was outside stationary. Eventually It managed to connect. Currently what I am doing is putting the watch on the balcony on the run mode (power save timeout extend) as soon as I wake up. It usually takes 20-30 minutes to receive a healthy connection. Also I sync the watch over pc at least once week so EPO file remains up to date.

I have still problems though. Some days it just refuses to find any satellites or tracking ends up all mushy.

My GPS acquisition is much slower too. It used to be within 10 sec if I am in the same location as the last use. Now it is 3-5min. If it acquires a signal, and I leave the run/OW swim mode, it will re-acquire with in 10 sec. However the next day itr is 3-5 min again. It seems to forget where it was and starts the search anew. I have GPS version 3.30, but kept the software at 9.60 (which otherwise works fine) to avoid all the nightmares people reported about 9.70 and possibly 9.80. So I can rule out that the problem (in my case) is caused by the new firmware. That said, I just enter the sport mode while stretching or put on deck while  it acquires a signal.

Using Garmin Express and following this might help - How Do I Get a GPS Signal Faster on My Fitness Device?

Good point, thanks. But syncing will also update me from 9.60 to 9.80, which I have been hesitant to do since all else works well. I guess there is a cost.

Actually I manged to sync with gc without updating the software from 9.40 (I miswrote). It worked, thanks seilogramp! I thought location files were updated from last use. Good to know. It acquired GPS in <5sec.

On the watch, I have a file ERR_LOG.txt showing that update from 9.70 to 9.80 never fully completed:

Build Type: RELEASE
Commit:6f1f5947db9aff6c6ebf9d7299ddaae73d40e641

09/26/20 13:23:20
RTL
errnum: 0x001
r0: 0x2000acf0
r1: 0x00000200
r2: 0x0010199d
Stack frame PC, SP: 0x00103a01, 0x2000a8c8
Call Stack - SP at 0x2000a8c8:
0x000b5ffb
0x000cfabd
0x0010199d
0x0010199d
0x000d0dcb
0x0000fdeb
0x0010199d
0x000cff15

...

(call stack continues)

After a factory reset, install of 9.80 is complete and GPS version is 3.30 instead of 0.00. Trying to get GPS signal.