Developer tools, Google console - why don't they work?

Question

Browsers

Gentlemen, ladies, hello. I'm currently learning programming and JS in particular. Faced with the fact that the necessary functions in the browser do not work.
Keyboard shortcuts Ctrl+shift+i, Ctrl+shift+j, F12 and through the interface menu do nothing. A search on google and habré also did not yield any results.

Resetting to the initial settings and reinstalling does not help. However, the Ctrl+u function works. And yet it doesn't seem to be exactly what I need. Who would help solve the problem, I never came up with, only this resource came to mind. I really hope that someone faced a similar problem and was able to solve it.

Installed OS build win10 19.09. Some time ago, in the browser settings, I climbed somewhere and "unchecked some flags", solving another problem. Unfortunately, I couldn’t figure out how to get there again, and I think I still wouldn’t understand where to poke there.

Such cases, I will be very glad to help, advice. I really don't want to reinstall the system.