A strange thing happened 3 days ago, where my keyboard stopped working suddenly. I restarted the laptop and then I couldn't type anything, not even my password.
After some hours I realized that the control key was somehow enabled the whole time and that's why I couldn't do anything.
So I disabled the control key from the keyboard settings and it worked for some minutes, but then the same problem happened again. I enabled the sticky keys feature and saw the control still enabled.
After I while I noticed that the down arrow key behaved as if it were the control key.
Specs: MacBook Pro Retina 2015 running macOS Mojave
Note: I've tried restoring, but now the keyboard shortcuts don't work anymore while booting up, not even booting from the USB.
QUESTION: How can I troubleshoot this further to fix my keyboard?