Samsung: Heart rate measurement stopped at Galaxy Gear Sport

I have a problem with SAA on my Samsung Galaxy Gear Sport with my Samsung S10 +: The heart rate measurement stops after a few hours. In addition, the alarm does not work on my equipment. I think the connection is lost somehow. I just turned off all “tweaks” on the battery, but the problem still persists.

SAA version: 20200806 (last available update)
Equipment Companion: 1.18 (last available update)