Cannot install Metal GPU in OS past Mojave

Hello,

I have a 5,1 flashed 4,1 Mac Pro that I'm struggling to upgrade. I was able to successfully install Monterey using the old gt120, however, when I try and install an rx580, it chimes, shows no activity, chimes again, and boots into recovery mode. The Rx580 seems to work just fine in Mojave and High Sierra, but as soon as I try to go beyond that, I get this issue. Furthermore, I encounter these errors with an R9 380 as well. Any help would be appreciated.