This bug still affects me on one computer using NVIDIA graphics, running Minecraft release 1.14.4. On that computer, there are no traces of Discord, so that is not the problem. Like the bug says, when hitting the windows key (which minimizes Minecraft) and then maximizing the window into fullscreen again, the game will visually freeze, however, it is possible to close the game by remembering where the pause and title screen buttons are and quitting the game normally, even though the image on the screen does not change. The game does pause on lost focus.
Here is a copy of launcher_log.txt:
[media]
NVIDIA Corporation
NVS 4200M/PCIe/SSE2
4.5.0 NVIDIA 382.05
This is the same bug report as https://bugs.mojang.com/browse/MCL-12595.