The AMD rx550 is by design not very powerfull, but did it really not work at all as in D.R.(version) won't start or won't show video in timeline or stutter performance wise? It seems to have 4GB of ram and good opensource driver support so with the right combination of distro/driver version you should come somewhere if you are only HD video editing...
Have you specifically tried a older AMD driver 21.20 with PRO-GL and PRO-OpenCL orca(legacy)? You may even try from a ubuntu 20.04 live distro with that amount of system RAM, installing PRO OpenCL only and extracting PRO OpenGL could also be possible. The next github issue sums it all up.
https://github.com/fat-tire/resolve/issues/8
https://www.amd.com' 'https://drivers.amd.com/drivers/linux/amdgpu-pro-21.20-1271047-ubuntu-20.04.tar.xz
https://gitlab.freedesktop.org/mesa/mesa/-/issues/6256
Or leave all this AMD fiddling around that even affects modern r/c-dna (big)navi cards and go nvidia which recently also has issues with their new partly opensourced driver...