Apple Watch Ultra and Shokz OpenRun Pro

Hello, I have been having connection problems between my Apple Watch Ultra and the Open Run Pro headphones from Shokz for weeks. While the devices can be connected, there are always interruptions when transferring music, so that the headphones cannot actually be used in conjunction with the Ultra. I have tried all the usual solutions (resetting the headphones/Ultra, updating the firmware, re-pairing, etc.). The headphones work perfectly with the iPhone (14 Pro Max). Does anyone have similar problems? Kind regards, Moritz