Fading/blurring sound

My setup is
Amazon Fire 4K stick connected to Vava 4K projector HDMI 1 slot.
Vava 4K Projector connected to JBL Bar 9.1 sound system ((the new one supporting Dolby Atmos) via HDMI ARC.
In the VAVA sound settings, selected HDMI out and RAW.

Facing an issue with this setup.

While streaming contents from say, Prime Videos ( was watching Grand Tour), the sound from the JBL fades…then it becomes blur…then it stops completely. To recover from this, I have to remove the HDMI cable from JBL and connect again. The problem repeats again say after 1 hour.
I tried content from Netflix and a few other sources too, all giving this issue.

I have tried 2 different HDMI cables ( both are supporting 4K streaming as per the spec) and both giving the issue.

Anyone facing this issue? Known problem, any solution?