Resolve to wix video gamma shift

Hi all.
I have exported two videos to Wix from Resolve via my Mac.
One as a Prores 4444 and the other as h264
Both have a significant gamma and saturation shift when played back on my wix site.
What I do not get is why wix retranscoded the h264 clip. H264 is what the Wix platform uses.
Any ideas whats happening with the shift? It seems like some process is being either missed or applied twice
when wix transcodes my material.
Thanks in advance.
J.

My first thought is, don't use QuickTime. The format has a long history of causing this type of problem.

Hi. Thanks for the reply.
Wix automatically transcodes to H264 whatever format I upload.

Just like YT, they also recompress whatever you send them. So, send them high quality.

But what you observe might be caused by your monitoring. My iMac's viewers or clean feed looks significantly different from what I see on my calibrated monitor via an UltraStudio Mini Monitor. I only trust the latter.