Unity WebGL Video black screen problem

Preview mode works fine but when I build the game, sound plays but screen is black.
I’m really getting tired about this. I need help please.
I’m trying to solve this problem about 1 month and cannot find a solution.

I tried to build 2019.3.10f1 and 2020.2.0a11 versions.

Same here @DryreL

Same… Did you find any solution @Dryrel @salomchat?