What could happen to the netbook keyboard after updating Xubuntu to 18.04?

Question

Keyboard

Netbook MSI Wind U90. Updated the distribution from 16 LTS to version 18. And the strangeness of the input began. To begin with, I didn’t accept a password (4 digits) in X, I wanted to flatter the recovery and reset it, but I noticed that the NumLock LED was on. I turned off the mode (using the Fn-button) and, lo and behold, it let me go. There is no item in the BIOS about the NumLock status when turned on, and before (and with other OSes too) it was always turned off by default. After reboot it is back on. I could not find a config with its status at startup.
But this is so, an annoying trifle, but what is already more serious. In the terminal (not in the emulator, but in F1...F6) I can't log in at all. It does not allow you to enter a password. Googling on this topic did not give the desired result, since everywhere they simply patiently explain that the password is not visible when entering. But here is another matter. Looks like that:

mycomp login: mark (Enter)
Password:
_

That is, after entering the login, the cursor jumps over the Password: line and, of course, does not accept the password, but nervously repeats the login request itself a couple of times, clears the screen and shows the invitation line again.
Never encountered this before. Another question is that I never upgraded distributions (Debian, *Ubuntu), but simply reinstalled, keeping user files and important configs (I don’t need so many of them)
Should I boot into recovery and reset the password (everything works fine in X, except for the misunderstanding at the beginning with NumLock)?
What could have happened to the terminal (keyboard chatter is unlikely)?
I would be very grateful for advice.

Answer 1

I asked myself, I will answer. Everything turned out to be ridiculously simple. Googling the problem gave the opposite results as expected. The main problem people had was wanting to have Numlock enabled at startup. And since people most often used x, they advised to install the numlockx utility, in which to write the On position in one line .
Desperate to find a recipe for happiness, I decided to install this utility and write in it: Off , no matter how stupid it may look.
What was my surprise when I found that the utility was already installed! Not by me, that's for sure. Even in clean, from scratch xUbuntu 18 it is already there. Logically! Users who do not need NumLock at startup (including those who have a netbook) are negligible. Most likely, the developers heeded the numerous groans and included this utility in the distribution, leaving it in the enabled position.
Removing numlockx solved the problem. On this device, it will definitely never be needed.