An active 1.12.2 window was already open without issues, but when I opened a 1.16 rc-1 window under a second account and installation at the same time, all settings and controls were reset. This includes key binds, video settings, sound settings, etc. Even my gamma was back to default, which I had edited by hand in the config file to a value of 1000.

The following day, I ran the game on the same account as I had the 1.16 rc-1 but on the previous 1.12.2 installation. While my gamma was back to the 1000 level, all in-game accessible settings and key binds were still default. Additionally, my flight speed for creative feels slower and when I am trying to place blocks there seems to be some extra delay between click and placement.

When previously playing with 1.16 snapshots or rc-1 as the only game instance, the gamma edit was never reset and stayed at the 1000 level, and my in-game settings and bindings were not affected.