Same issue and already received a replacement phone. This issue is also with the Note 8 but I'm aware of and I agree social media should be contacted and blown up over this. Just wanted to hang on to its customers start figuring out how to resolve these issues quickly.
Give this a shot;
Settings>Apps>Click on the three dots at the top right corner>Show system Apps>Device Maintenance>Storage> Clear Cache/Data
Settings>Apps>Click on the three dots at the top right corner>Show system Apps>Phone (All 3)>Storage> Clear Cache/Data
I disabled the lookout and had no problems with the phone restarting. I did however found out that android nugget has an update in the background it will randomly restart the phone even if it is a very small update.