Can someone help me with this strange one.

I have a TCL TV and am using HDMII for Firestick and HDMI2 for a Humax HDR 1100S recorder.

When trying to playback some recordings on certain Freesat channels made on the Humax there appears to be no sound.

However, if I pause the playback, switch to the other HDMI (#1) , and then revert to the Humax (#2) the sound plays!

This doesn’t make any sense to me but it works every time.

Any suggestions as to cause – and a solution?