No, it’s not a performance problem but I think it’s unnormal.
I looked at the private tab of the resource monitor and it’s still the same:
Constant 16.8MB after starting the PC. Constant 16.92MB while and after playing some music. That’s fine.
Starting the GUI and bam!, the cycling starts. Closing it and I’ve got an even bigger range. Restarting the GUI brings back the smaller range.
For me this looks like a GUI problem since I can keep the memory constant at a very low level by never opening it. And I can see no reference to processing sound or silence, that doesn’t seem to have any noteworthy impact on memory.