To clarify the bug a bit:

I have a normal QWERTY keyboard. Some keys, like a, change into ą, when ALT is held. When I hold ALT and try to type, nothing happens. I thought perhaps you are filtering out Polish chars, but you can copy Polish text from outside the game and paste it just fine.

I am on ...

Yep

Sure, there you go

Thanks!

At least when the game is set to English, it rejects using Polish characters to name, for example, space platforms. I have my keyboard set to Polish and to get Polish characters, I have to enter notepad, type the name there, copy it and paste into game - then it works.

In older versions of Factorio ...