Thanks!
Firefox is my main browser so it's probably not just it. As long it not just a game but my own engine (Opengl wrapper – flgl and UI system based on domkit) and i plan to use it in many other games, it is very important to me.
I suppose it somehow linux-related and maybe gpu related issues.
May I ask you to assist in finding the issue? Is it ok if i try to make a plan and DM you later? At first i'd rather try to test a HL build on your side since it should be also crossplatform and in theory i can build it under windows. But I'm not sure since i should find compatible ndll. Or look for cross-compilation. Or install a linux myself...
I also have a hypothesis it can be related to gl scissors i use to implement scrollbox. I should also look to the stream again. Is it accessible?