I've been seeing that from time to time. Steps to reproduce:
- screen wake on gesture: enabled
- start Exercise app, Run (GPS)
- while waiting for GPS screen will go blank
- turn wrist, no reaction
- tap screen, screen wakes
- tap to start run
- instead starting run, screen goes dark again
- repeat several times until it will allow run start (yesterday I was already 500m into the run).
I have experienced that on several runs (recently, just yesterday during Parkrun but issue isn't occuring every time). Because of that, I usually start tracking run long before the run starts (especially, races so I don't play with watch after started running).
