Incorrect protobuf schema compatiblility checks

[paualarco]

The schema registry running locally on the docker image with tag 5.2.0 is not returning correct schema compatibility responses for protobuf schemas.

What happens is that when I register a schema A, whatever schema I compare with returns compatibility: true, even if it is an empty one, whereas my expectations is that it should return false, since the changes are non backwards nor forward compatible...

Is this feature not supported yet using docker image or am I missing any concept?