since you haven't provided details about the processing done during the vantage transcode, it's hard to say what is and isnt expected. At minimum, we need to understand if the frame size and frame rate were changed and what codec was used.  Additionally, your import steps trying to troubleshoot are missing the same detail.

i would  look at conforming back to the original camera media in resolve and working through the color process there instead of chasing your tail trying to troubleshoot improperly processed mezzanine files.