Today marks the second day my 745 hasn't recorded any sleep data. I also noticed sporadic wrist HRM behavior. I started a run today and noticed no HRM data was being displayed. I stopped the run, restarted the watch, and tried the run again. This time HRM data was being recorded. I can only assume the lack of sleep data is related to this HRM issue. Never experienced these problems before. Anyone have a solution or know what's going on? Current software version is 13.70.