Colonists Stuck

I just tried my hand at creating two homes for colonists. Both structures are similar with the deed placed on the ground floor, but each home also has a small "basement". Both colonists repeatedly beam up and down, getting stuck on the basement floor. I'm not sure how to fix this, I've tried a few things like making the floor directly beneath the deed solid instead of a platform. No good, they still beam right through to the basement.

*sorry if this is the wrong forum for this, please move if needed*