When import video in final cut pro it’s uses wrong resolution
You were on the right track with Spatial Conform -> Type -> None, but you also need to adjust either the fill or the sequence settings.  You are trying to put a round peg in a square hole and FCP is trying to guess how you want it to make the peg fit.

You've told it you don't want it to stretch the peg. (This makes sense as a default because some formats do not use square pixels, such as anamorphic widescreen or NTSC DV.)  Now you need to tell it either that you don't mind if the peg is too small for the hole (prevent scaling to fill) or adjust the shape of the hole (altering the sequence/timeline settings).

I unfortunately can't give you specific details on how to do this in FCP as it's been quite a while since I last used it seriously, but the general concepts are basically the same across NLEs.