Railing doesn't go all the way when placed on one side

If you place stairs one block away from the room they lead into, they create this little one-block floor landing. Normally this thing has railings added along with the stairs (since the square bit is not actually a floor, you cannot add a fence there). 

In the recent update, if you only place railing on one side, the railing doesn't cover the top part (but double-sided railings still behave fine). 

This seems to happen on any wall height (and on platforms) with all stairs and railings.

Also a note - this behavior can be forced on double sided railings (which is good) but you unfortunately cannot force-add the railing on one side