Items dropping out of inventory

Every time I craft an item, since this afternoon, it has fallen to the floor/ground, instead of appearing in my inventory. With the exception of cake: that just disappears and is replaced with the empty buckets I had the milk in. I've only encountered this issue in survival mode, since I don't craft in creative. Additionally, and this might be unrelated, I can't switch between items when in creative mode, unless I drop the first item from my inventory then swipe repeatedly on the one I'm trying to use.