Any ideas what why this is suddenly happening?
Check the compressor mounts but odds are that the clunk is inside he compressor.
The compressor is on it’s last legs.
It may run like this for quite a while but can no longer be trusted.
If you have a place where the clunking will not drive you crazy and need a beer fridge that is what I would do with it.
Gets expensive if you loose a bunch of frozen food.