Update #1: Want to clarify RE: color: I did the color in Adobe CC 2017 and have not touched the project since then; Once I opened it in 2021, my color information was completely off and no longer matched what I had done in the project, which you can see in Screenshot #1
First, there were some major changes to Lumetri between the 2017/2018 versions.
Second, that Color Balance effect is an 8-bit effect, and is not GPU-accelerated. It will take the computations of the clip down to 8 bit rather than Lumetri's normal 32 bit float precision. Not a good thing to do.
I would rework this now and I would not use an 8-bit effect like Color Balance. Yea, it's a pain but that is the way to get the best work done at the moment.