I just changed my macpro 2013 - Mojave - compressor 4.4.8 by a mac studio - monterey - compressor 4.6
I used the exact same settings to transcode a 30s movie (prores 422) in H264
I put a copy of the settings (in french!)
I transcoded it with Compressor 4.6 and the result is bad (pixel blocks - not sharp)
I tried to transcode the same movie with compressor 4.4.8 ans the result is good
I had to uncheck the "multipass" option and set to 13000 kbps in compressor 4.6 to have a good result
I don't know why compressor 4.6 gives a bad result with the same settings...