Adding cards to Sideboard that are already in the Mainboard

{"ops":[{"insert":"Interesting. When I do this, the card appears on the mass edit list both for the quantity in the mainboard and for the quantity in the sideboard (the later of which says 'sideboard' after the card name). Are you adding the cards to the sideboard via those already in the main deck or are you adding them from a new search?\n"}]}

{"ops":[{"insert":"I'm adding them as a new entry. They show up at first in the mass deck edit list, but disappear as soon as I click save changes.\n"}]}

{"ops":[{"insert":"Odd, I'm unable to replicate the problem. Hopefully one of the devs has an idea of what's going on!\n"}]}

{"ops":[{"insert":"Hello, \n\nDev here, I attempted to recreate the problem you described but didn't have any luck. I was hoping you might be able to elaborate a bit so that we can get this fixed for you. From what I understand, (please correct me if I'm wrong here) you're trying to add a card to the sideboard from the mass deck edit, with a card that's already in the deck.\n\nWhat browser are you using?"},{"attributes":{"list":"bullet"},"insert":"\n"},{"insert":"Are you in the sandbox or a created deck?"},{"attributes":{"list":"bullet"},"insert":"\n"},{"insert":"Are you using the card search or inputting text in the text area of the mass deck edit?"},{"attributes":{"list":"bullet"},"insert":"\n"},{"insert":"Again sorry we can't figure this out a bit faster for you, but hopefully we'll be able to get it sorted soon!\n\nThanks again for the bug report,\n~ Michael\n"}]}

{"ops":[{"insert":"Hello! I'm using Google Chrome. And yes I'm using the mass edit, attempting to add them via searching for the cards, and selecting \"sideboard\" in the category drop down. In a created deck, not sandbox. \n\nEdit: also does not work on a mobile web browser for me, just tried again. \n\nI successfully find the cards, list them as sideboard, click add, they show up at the bottom of the list, I click \"save changes\", they disappear and at the bottom it says \"all card changes have been listed\" or something to that effect. I close the window and the sideboard still only shows the ones that aren't in the main deck. \n"}]}