Heart Rate Download Not Working (EPIX Pro Gen 2, HRM 8.8)

 

In the report description: Device and Version of Software:
EPIX Pro Gen 2, 18.16 (official release, not beta!)

Issue Description:
The watch can no longer download the heart rate data from the chest strap (HRM-Pro (8.8) as well as HRM-Pro-plus (8.8)).
When I try to download the heart rate after strength training, the watch gets stuck on the status message "Processing Data." This means the watch connects to the strap and begins downloading the data, but it hangs during processing. I haven’t tried this after a run yet.
I can only turn it off forcefully using the "light" button.

And there is a sever power drain since 18,16 form me too

If needed I may provide the activity files.