Description:
I'm running Minecraft thanks to Lutris, and when the fullscreen mode is enabled and I press Alt + Tab, nothing is working correctly. First of all, the task manager is frozen in a past state ; the digital clocks says me anything and is frozen, the tasks shown on the task manager aren't the good ones... Secondly, the VSync is absolutely dying when I alt + tab in another app, wich wasn't happening in Windows. I must precise Lutris isn't the problem because I had installed Minecraft in Linux without it, and the issues were the same, everything was the same.
Reproduce the bug :
To reproduce the bug, just install Minecraft on Linux, and Alt + Tab. I don't know if the bug is here with others distros or another X server.
Minecraft only supports Java 8, please check if this also happens when using Java 8 and not 14, and create a new report.