Hi, when opening the metrics (shift+ctrl+o) the fps drop to 10 or less, in adrenalin 20.4.2 this did not happen.
CPU: Ryzen 5 2600X
MB: MSI B450 Gaming plus
GPU: Powercolor Red Devil RX580 8gb.
My ASUS RX 580 4Gb DUAL OC also have this bug with superposition of the performers (GTA Online 60fps but this overlap of metrics show 23fps or 13fps and the Game enter in slow mode with GPU in 300mhz only)
I have returned to 20.4.2 with windows 10 v.2004 and everything goes right for now , there are no fps decreases , and the adrenalin program works normally opens , closes and navigates through without apparent delay.
This is listed as a Known Issue in the release notes, although it does not specifically mention your GPU it sounds like the same issue.
Radeon RX Vega Series and Radeon VII graphics products may experience performance drops when Performance Metrics Overlay is open while a game is running.