There isn't anything like a "gender neutral" word in Polish...

Or do you mean neuter? Then no. "But" is masculine. "buty" are 'not masculine-personal plural' (they are not masculine persons).

Well, "but" is the only starred answer, "buty" is wrong (it could be among the words possible to click), so "but" really must have been there... we'd need a screenshot to check this issue.