iPhone X keeps restarting IOS 11.2.2 jUST UPDATED

First you have to clear that there is any issue in modem firmware.Check the meid of the phone by dial *#06#.If imei shows there may the hardware issue or wait for new update coz downgrade to old version is not possible on new generation iPhone.

I’m having this issue too. Try turning your WiFi off. For some reason when I’m connected to WiFi my phone restarts every 3-5 minutes but when it’s on LTE it works fine. I’m going to Verizon today to try to get a replacement phone

I'm having a similar issue, but it's spread out to every hour or so. My screen will go completely black. For a minute or two, any music I'm listening through headphones, or anything I'm watching on Airplay, will still be playing. But I'm unable to do anything during this time as my screen remains black. Once what ever I'm listening too, or watching, stops playing, my screen will remain black for another minute. It will then reset and prompt me to enter my password and everything is almost back to normal. Wherever I was in my media when the screen goes black, my phone will start playing from that moment as if what I was listening too while it was black, did not happen. If that makes sense.

iPhone 7.

Update from my last post, turns out WiFi wasn’t the problem, it eventually went away but as soon as I’d restart my phone manually, the problem would come back and this past time it didn’t go away. I ended up going to the Apple store and got a replacement phone for free and I no longer ha e that issue so if you haven’t gotten it fixed yet I highly recommend you do that.