Whenever I open a deck I was currently running mystical tutor or enlightened tutor, They get removed for being illegal. I then re-add the cards and apply styles to the old versions instead of the Avatar versions which makes them disappear but does not reduce the deck count.
I also have the bug still with double Commander slots even though I'm not running partners which gets in the way. I have to remove the commander in order to re-add him just to clear up space. Either remove the second empty slot which takes up an entire column or move it below the initial Commander so it's not taking up an entire column. Same thing with companions.