I have found the with private relay on when you look up your IP it gives an incorrect result eg mine will say I am in the USA
but with it turned off it resolves correctly
found out because I did a BQM and got a completely Red graph but I still got 1 gig on a cat6 connection but with the correct IP the graph was good with one packet drop around 0100hrs but the rest was low yellow spikes
these are my empirical observations not based on anything else but then the millennials ( grandkids ) say all adults know nothing 😎