AW4LTE + watchOS 7 betas crashes during running - battery drops 100 to 10%

Hi,
Since using watchOS 7 Betas on my AW4LTE the watch crashes / restarts after 20 to 40 min during the running activity. After the restart, the AW shows below 10% battery left (started fully charged). Another restart or putting the AW on the charger brings the "original" battery charge "back".
I performed a hard reset as well as decoupling and recoupling the AW4 with my iPhone 11 Pro Max. This did not solve the problem.
Any ideas?
AW4LTE + watchOS 7 betas crashes during running - battery drops 100 to 10%
 
 
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