I used the same pc, (dual boot) I also use the default keys given by Factorio.
I don't know if the key-set is different, I think they are both US international, with a € sign on the 5.

Ubuntu calls the enter key "return" and windows calls it "enter" I think. (To enter a vehicle)
Factorio then sets ...

I play the game on both Linux and Windows via Steam.
When I switch between the two platforms the game changes the key binds to "unknown" for some keys.
This is probably due to a different key mapping of the two systems and an one on one transfer of the configuration file.
I don't know if this ...