Latch locks when door handle pulled down
Are you sure the handle wasn't removed?  It's certainly a slight misalignment so that the latch is binding.  It could be that when it was rehung the door shifted slightly, or same thing with the handle being removed and replaced.  Either way, I'd loosen the handle enough that you can shift it very slightly but have it hold the position while you test it.  When you find a position that eliminates the binding (which I bet you do), retighten it.  If this doesn't seem to be the problem, let me know.