Just sanity check stuff. Try using Firefox browser. Back the last time I messed with this problem in 9/21, not every browser produced the same results, and you could go around in circles. From that thread, I showed a mesh in Firefox, which looked the same in Blender.
I also showed on from Chrome:
The chrome & Edge browsers, at the time, both showed like a light blue green film on them. I proved that, at least to myself, because the colors all match if you form your image from a readPixels() call.
Best to compare different browsers to ensure against this.