Client 'unable to keep up with' and 'exceeded max' pending messages

I’m being plagued by these two error messages:

They seem to be being caused by a (fully kiosk) wall panel but I have no idea why.
I have tried countless things including what I considered to be a nuclear option which was automatically navigating to a completely blank page when the room is unoccupied.

All to no avail.

I know there have been other posts about this but nothing seems to point to a solution.

It’s a long shot but all this may or may not be affected by this error message (which I have no idea why I get either)?

Thanks for this post! i have the same problem, but after disabeling Fully, my HA is working fine again.

Maby it is a long shot, but i have enabled MQTT on fully (which is in beta mode) perhaps this could be the issue?

I am not having MQTT.
But I see these messages rather often.
I suspect it’s somehow related to Companion App - using the app for iPhone & iPad.

This is strange, because i am not using any companion app for either IOS or Android