The Beta version of Resolve Lite 12 is out. Unfortunately there is a bug. Directly loading MXF files into Resolve somehow does not pick up the audio track, or if it does, displaces it. If I first put the clip through Catalyst Prepare and the export as XAVC the identical clip loads with audio. I've told BlackMagic and they recognise that it's probably a bug and recommend to use 11.3.1 for now. From BM-
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It seem like a bug in Resolve beta 12 . It seem to work with Resolve 11.3.1 .
You may want to try Resolve 11.3.1 for now .

I will feedback to the developer for them to look at."