I am experiencing the same issue. I cannot get DaVinci to find my media, and I have gone to my presets, told DaVinci where all my media lives, even double checked on FCPX but nothing, no way to have Resolve to open my files. Sometimes it will find some files, but not all of them, for instance, out of 63 files, it can only find half, and so those are the only ones shown in the timeline, everything else appears as if it was “missing media”. I don’t understand the logic of this, since all the files live pretty much in the same place, just different subfolders.
I wonder if it has to do with the editor using transcoded files versus original media. Thoughts??? Any help is welcomed.