How to disable full screen exit in browser?

Question

Adobe Flash

How to disable exit from full screen mode in the browser when pressing alt+tab (various flash content: videos on yourube, twitch).
Previously, everything was fine: when you expand a video on youtube, and then press alt + tab, a window was displayed separately in full screen mode, but now it just turns off and you have to expand it again.
PS Flash player reinstalled.

Answer 1

Full screen flash and full screen browser work differently.
Now YouTube uses HTML5 Video, so the full-screen mode behaves differently. You can't do anything about it.