Since today, I can't use the on-screen keyboard, it's bugged like hell.
It's very unstable. It worked in Firefox search bar (where you write website address) once, after closing and opening the program multiple times.
It's bugged in Edge and Chrome, too.
It doesn't work at all in 's search bar or in [url=http://duckduckgo.com]Duckduckgo's.
I'd love to uninstall the OS and use one of the many superior systems, but unfortunately I need it to play my favorite games, so changing OS is not an option, I'm afraid.
Only using physical keyboard is also not an option, I need the on-screen keyboard app. Security reasons.
And yes, I tried turning the PC off and on, before someone asks!

Solved it!
If I could mark my own post as solution, I would.
I suggest you blues add this. Simply remove the reputation boost.
Good day/night.

Please do tell what the problem was and your solution to it! It might be useful to others with the same problem.

I reinstalled browser, and stopped using Winblows virtual keyboard. I'm using a virtual keyboard freeware from another company now.
As to what was the problem, read OP.

I must have been tired while reading your first post...