Keyboard button backtick/tilde become section symbol after replacement

Solution 1:

for me it was a matter of configuring the keyboard through Settings -> Keyboard and then "recognising" again "unrecognised keyboard" (i.e., my plain keyboard which was plugged in all the time) and then setting its type to US (ANSI) instead of European (ISO).

Solution 2:

If you now have an extra key to the left of the Z, that is where you should find backtick/tilde.

(British and English International keyboards have this extra key and move those characters to it)

If you want things back where they were, a custom layout can easily be made with this app.

If you do not have the extra key, then you have the keyboard type being recognized incorrectly by the machine, which is another problem. But you can still fix it with a custom layout.