A while ago there were some known issues with volume settings changing — are you running all the latest firmware/code? Gerry and team should get you sorted out, esp. if you submit a ticket for it.

Edit- looking at past posts here it seems like you’ve had this problem from the get go, over a year now? No resolution from multimorphic? Almost seems like a faulty amp or issue with it if no other owners are experiencing this? I do recall whenI owned a P3 that the glass would rattle on cannon shots with the bass but I kind of enjoyed that.. it was punchy for sure but you could crank the other volumes as well to match it.