Polar H10 not working well on 17.23

I have a Polar H10 belt that worked well on the FR 945. But it doesn't work well on the Enduro 2. If the belt is connected to the watch via ANT, it shows the pulse but keeps disconnecting and the pulse jumps up and down (battery is at 70%), but via BT is even worse, it doesn't show the pulse at all. Does anyone have similar problems? HRM Pro Plus works without problems. I have never tested this band on previous firmware versions.