Bluetooth 5.1 won‘t work with the WINDOWS Garmin TACX App!!

I used for years the TACX_Software on my WINDOWS 10 System. After the ANT-HRM did nor work very stable, I decited to change to the WINDOWS Garmin.TACX App.
The App did not connect to my bike and the HRM-Belt - I tried ZWIFT, ROUVY and BEKOOL and all these Apps are working perfect with all sensors - Bike and HRM.
Any ideas what‘s the reason for that problem? Or better change the System? Regards to all - Thomas