About six months ago, our attic door stopped shutting all the way. Any ideas on how to fix this?

tighten the screws in the frame and around spring brackets

also, maybe the guide rail is catching
you can just bend it back if that's it

If none of those work, then you can always sink a couple deck screws in it to suck it up so it seals. Annoying I know when it comes time to access the attic, but that is what, like 4-6 times a year, maybe.

Might be a bad gas strut. I had to replace mine a few weeks ago because the geniuses that installed the attic access put the sharp end of the mounting screws against the strut. After 3 years the strut casing was fully breached. Afterwards access door wouldn't shut completely like that.

Bought replacement struts (100lb) & install was pretty easy aside from compressing the new strut. Used rachet straps

Does it have insulation/styrofoam panels attached to it or between the panel and the ladder? Mine does and sometimes the foam shifts to the side and keeps it from closing properly.

i have this same issue on a home we moved into, and haven't figured out a solution yet. Everything online says to replace the whole ladder assembly, which is not happening except as a last resort