Can anyone offer any advice on why the powlim might not be working on my RX 480 8GBs?

I'm using the following settings:

-amd -acm -powlim -20,-20 -mclock 2100,2100 -rxboost 75,75 -gt 54,54 -gpus 1,2

AMD driver version 20.12.1

Occasionally im getting crashes and the memclock gets stuck on 300 so i have to manually set it back in the radeon software too?

using the settings above i get around 28mh/s for 60w perr card (XFX RX 480 BE 8GB cards)