Puzzling behaviour

I have a piece which contains both midi and audio segments.

When I open the 'Manage Audio Files' dialog, there is a warning

about sample rate mismatches between files (44100Hz) and Jack (48000Hz).

These actually play fine but I assume that things would be better if I 
adjust

Jack's settings to match the files, so I do so using "pw-metadata -n 0 
clock.force-rate 41000".

(I am using Pipewire's Jack implementation).

Now RG is happy but there is horrendous latency and the audio is 
sometimes seconds behind the midi output (CPU=~23%).

This doesn't make sense.

Does it?

TIA,

Chuck.