Audio Sync issue after latest August 2021 update


I have what seems like a sync Issue with the latest August 2021 update.
When Kodi is running, even when just sitting there on the menu, I can see an Audio sync issue.
Checking my AV Receiver, I see a constant drop of the AV happening.
That is, I see the LEDs for showing me what connection is currently on the AV side going off and on in a cycle.
First I though I had some bad cable or something, but switching to another HDMI port on the TV or using an App on the TV does not show this issue.
It is also noticeable once you play a Video file that Audio is dropping every few seconds.
I did some testing, and it seems to only happening on 4K UHD resolution, 3840x2160p.
If I switch to Full HD 1920x1080p Audio sync is fine, and no drops happening.
Setup is a Samsung TV with a breakout box with SPDIF to the AV Receiver.
Any help on how to narrow it down is much appreciated.

This a known bug which showed up only recently. Please set your GUI to 1080p, which we recommend for all users.

You should find most 4k videos play OK if you set refreshrate switching to On Start/Stop. As far as we know, only 4k videos with 44.1kHz PCM audio are a problem - you can work around that by setting audio to a fixed rate of 48kHz until we find a cure.