F5 reboot under outdoor cycling activity.

Does resetting defaults on the fenix 5 resolve the issue? (Settings -> System -> Restore Defaults) No
What software version where you running? (Settings -> About) both of 7.7 and 8.0 (APAC)
What sensors were you running? None
Has this happened on any other activity type? Running app
Did you have the fenix paired to a phone? Yes
If so, what type of phone and was the screen ON or OFF when the issue occurred? iPhone X with iOS 11.3 / iPhone was in a pocket, so I couldn't check whether it was on or off.
Was the Connect Mobile app running when the issue occurred? Yes
If Connect Mobile was running, was it in the foreground or the background? Background
Was LiveTrack running when the issue occurred? No
Did any out of the ordinary events occur on the phone when the issue occurred? No
List of Connect IQ Apps, Widgets, Data Fields or Watchfaces installed on the device? No
If Connect IQ apps are installed, does uninstalling them resolve the issue? N/A
Was there anything different about the activity when it happened? (Different bike, new handlebars, sensor, …) No

Went for another ride today. HRM-Tri, speed and cadence sensors connected, iphone on, but bluetooth (and wifi) turned off. No GC running.
No reboot today! Woohoo! Just a strange peak in top speed. 136,96 kmh and average 23.9.. (riding MTB)
Seems like it is a problem related to GC and/or bluetooth connection.

with Fenix 5x os8 and iPhone X iOS11.3 I tried something that seemed to work this we. Turned the watch on 30mn before starting the ride. during that time, there must have been 5 sync (???). During the ride I only had 1 reboot vous at least 6 last ride...

Another bikeride today. Started with iphone on, no bluetooth, no wifi, not sure about GC. HRM-Tri, speed and cadence sensors connected.
Reboot after 27 min. Turned off telephone completely. Another reboot later. Can it be the speedsensor?
Whole session lasted about 1 hour an 45 min. About 50 km.
F5 still running public beta 8.54
:mad::mad::mad:

Bekkedlen next time try to leave your watch on and close to the telephone a couple of hours at least before starting your ride. GC seems to be syncing with the watch many times when you first turn it on. turning bluetooth and wifi off does not stop the BLE connection with the watch... Let us know what happens, will try myself for the Sunday ride...

I am having the same issue. Been happening for a couple of months but seems to be more frequent lately (especially more frequent since I got a Vivimove hr last week which I'm wearing as my everyday watch instead of the Fenix 5). Mine only seems to happen when it auto-laps at my first km. It reboots and then adds like 0.96km to the total distance and comes up with the resume screen. If i resume the activity the final numbers for the activity are all screwed up. I will have to check phone when it happens and also take note of whether it happens when I dont have the phone with me. I do this activity about half the time without the phone, I cant remember if there is a relationship with the robooting or not. Will pay more attention.

The whole connection to the app has been a little off since I added the second device. True up is a little buggy and slow, that's for sure (though it does work eventually, it's just not as seamless as I'd envisioned!)

eta: the activity is walking, have never had it happen on the bike but i bike indoors on a trainer so no gps (not sure if the gps has anything to do with it, but the distance always gets screwed up after the reboot so it might)

Same thing happened when I did the activity and didn't have my phone on me. Will try turning off auto-lap today and see if that fixes it. Super annoying, I haven't had any data recorded in a week (because I'm deleting the screwed up activities), plus when it happens it sometimes erases all the step data from the day and starts over, which doesn't exactly help my standing on the CountIt board at work!

Well, I have solved my problem by turning off auto-lap. No reboot during activity. I guess mine is a different issue. Annoying that I can't use auto-lap though.

Bekkedlen next time try to leave your watch on and close to the telephone a couple of hours at least before starting your ride. GC seems to be syncing with the watch many times when you first turn it on. turning bluetooth and wifi off does not stop the BLE connection with the watch... Let us know what happens, will try myself for the Sunday ride...

When I'm out for a spinn 0700 in the morning, it's out of the question to get up at 0500 to start a ritual like that. Even if it would help, its not gonna happen. Thats not the way it should work. But thx for the suggestion. Btw, reboot occur even without phone with me..

Well, I have solved my problem by turning off auto-lap. No reboot during activity. I guess mine is a different issue. Annoying that I can't use auto-lap though.

Auto-lap has been off all the time, still have reboot.