FCPX / Davinci Resolve Round Tripping - Seeking someone with experience

I am trying to collaborate with another editor. I use FCPX, he Davinci Resolve 17. Both platforms are fully updated as of this post. I send him rough edit XML file, along with proxy files, from FCPX. He can open in Davinci, connect the proxy files and make edits on his end fine. When he sends back new XML file to me (in our test he retimed a couple clips and added cross dissolves), I cannot get the clips in his edit to relink with the full res clips on my system. Project opens, but clips are Missing and cannot manually relink. Error message is "The original file and new file have different audio source and channel count..."  We are trying to figure out, if anyone has seen this error before and can help, please and thanks. 

I just went into DaVinci - and all our compound clips or clips with speed changes did not translate. How did you deal with those issues? Sounds like we're going to have the same issues as you also once we get the xml back so I will keep an eye on this thread for that.

I have the same issue getting multicam clips to work. We abandoned a resolve turnaround for one recently that was shot with FX9 as main cam and Sony A7S iii as b camera. None of the A7SIII clips came over and importing manually and changing the time code to zero (a common trick) did not fix the issue.

Instead we had to export a clean master in 4444 and go from there, but you have to be careful with transitions like flow. They do not always translate well and we had audio sync issues when bringing footage back in, And that was just for grading mainly with another 4444 master export.

I think FCP Badly needs the collapse multicam function from the legacy software. It was really made for this. I’d suggest using feedback.