Ultra 3 Watch display turns off after any arm or wrist movement.

Hi. I purchased an ultra 3 watch about a month ago, working normal. A couple of days ago while running I took a fall (I’m okay) and since then my watch, with no physical damage, is not acting as it used to. After the fall every time I checked my watch I noticed the display was on turning it off by covering the screen. I had my display to turn off after 70 seconds, so I switched to 10 seconds and back to 70 and issue solved. Problem is that the display turns off every time I move my arm or wrist which didn’t do before. All my settings are the same as before the fall, I turned it off, on, restarted, reset, unpaired and re-paired a couple of times and it’s still not working as it used to. Best Buy diagnosed it and didn’t find anything wrong with the software or hardware. Called Apple following Best Buy’s advice and same result. Apple referred me to a local Apple service provider and they say it’s working normal when I know it isn’t as it was before my fall. To recap, problem is Ultra 3 watch display turns off with any arm movement even if it’s supposed to turn off after 70 seconds. Any advice will be greatly appreciated. Have a nice day.