bug: I can't add cards to the sideboard when building a deck

platform: ios (ipad)

reproduction:
* create a deck with 60 cards (see the deck in my account called "[std] grix wiz 2" as an example)
* save the deck and then come back in and edit it
* add some new cards to the deck (I added 4 x negate)
* attempt to move those new cards into the sideboard from the main deck area by opening the sideboard panel and dragging them in (this is on ios for me)
* note that you're not able to move them to the sideboard
* If this does work in your case, be persistent and try to figure out the variable that causes it to break. exit from the save, play a game, come back and edit, try to drag new or existing cards into the sideboard, etc. This sometimes works and sometimes doesn't but it's been consistently happening for many many months.

other notes:
* this bug has been around for at least the past 6 months and I've heard several streamers complain about it on various platforms, I'd be very surprised if it hasn't been reported already
* this prevents me from playing "best of 3" since I can't really build a sideboard