Make sure you've got the latest updates - both Poolside and Unsloth updated about a week after release, and that you're running via llama.cpp (I've noticed on the same model and same command line arguments, ik_llama.cpp loses quality for me).

Also just in case you didn't see it, Laguna S 2.1 was having issues on MXPF4 but people on Q4 and Q6 couldn't repeat the problem.