When building decks I find that sometimes the "+" icon on my cards will gray out when not at 4 qty, and this will happen even if there is no copies in the side board. Once this happens, I am also unable to drag from the collection into the deck anymore.

Exiting the deck building and re-entering it does not work, the only way to deal with this issue is to completely restart MTG:A. After the restart, it will work as expected.

Lately it's happening so much it's becoming obtrusive, probably because I'm using it more for an experimental deck.

Steps to reproduce:
Simply spend enough time building a deck, and dragging cards around, and using the +/- user interfaces as well. I am using windows 10.