Researched the topic even further, studied DaVinci docs. Looks like AV1, H265 and H264 are unsupported by DaVinci Resolve on Linux if you have an AMD GPU, even on the paid Studio version. No such problems with an NVIDIA GPU.
Will probably resort to using DNxHR with no further re-encoding, or set up a script that will re-encode it back to AV1. Oh well.