965 restarting endlessly

Contact the Garmin support line

See if this helps

forums.garmin.com/.../stuck-in-boot-----looping-during-booting

Turn off the watch (log press of light will do it in about 15-20 seconds.)

while pressing the light button, connect to external power (like a wall charger).  Wait a bit and release the light button.  The watch should boot fine. 

I have the same issues today with my 965. When I start run mode it just keeps on restarting. I will return mine back and get back to my 5 year old fenix 5 with which I had 0 problems. Big fail Garmin. AVOID! AVOID! AVOID! FR965

Strange had no such issues myself

Hard stop finally solved the problem. 

We should expect some bad surprises for the next weeks; like always when they release a new model. We know it, and yet be still buy it day 1... :-)

Hello. What do you mean by "Hard Stop". I have the exact same problem. Thanks for your help.

Just return the watch. It’s unusable. I have contacted Garmin and they say they will probably fix it in some future updates but they don’t know when exactly. 

Hello,

I turned off the watch and pushing the power off button and maintaining it for a good 30 seconds. 
i restated the watch connecting it to my computer and synced it with Garmin Express. 
it worked, no worries since.