vivoactive 4/4s (now running sw 6.90) powers off randomly, including when interacting with Wi-Fi

Since update to 6.80 my watch was turning off without any reason.   Even when charged 100%.  I discovered that it is happening under two specific circumstances.  First, if I search for WiFi network it attempts to search and then after about 10 seconds shuts down.   I have to power back on to get this to work.  Second, during transfer of data activity it will shutdown after I select save.  Fortunately for the later, I can turn watch back on and after few times save the activity.   Last night during normal wear it just shut off.  Since I run PulseOx monitor this would also fit.  I turned the phone back on manually and it was fine.   I plugged in for good measure to charge.   There clearly is something wrong with this software update.  How to I rollback until you find and fix the issue?  Is there some other workaround?

I meant watch not phone.  Sorry for typo

Just had the same issue start happening.  Any news?

Same issues here!  Help!

Current sw version for vivoactive 4/4s is 6.80.  You can use Garmin Express to update your watch.

Same issue.  Watch was randomly shutting down at night.   Thought it was related to the 6.9 update. Rolled back to 6.8 and pinpointed that the watch is shutting off when searching for Wifi. 

Update for me..... My watch died soon after.  Got an out of warranty replacement for $150.  Not bad.  Credit card warranty covered the cost. 

Is there a fix for this yet ?? It's driving me crazy as keeps loosing connection. 

I use my watch to track stats for health reasons. 

SW 6.9 and wifi 2.6 

Sounds like the battery is too low. Weak with age?

Wifi consumes a lot of power in a short time, the battery can no longer deliver, collapses, the clock goes off.

The watch is only 14 months old.   Very disappointed if that is the case. All of my other Garmin products have been great.  

Strange too how so many  other people are getting this issue since software updates. 

Mine was fine until this too. 

Can you change battery in these watches ?