The 3.5.5 Stable Update seems to have carried over with it a bug in the overlay where the GPU shows 200mhz - 1040mhz constantly.
It doesn’t seem to happen on every game and performance seems unaffected so maybe it is just an overlay issue, but it is in a month old bug report here from 3.5.1:
Was surprised they skipped beta. Turns out it’s nowhere near “stable”