I don't think it's a big deal, because sometimes I do the same thing as you guys, and so far there haven't been any warnings or blocks on our accounts. But it would be better to use two different devices.
It is possible that you have not encountered such blockages for the reason that you did not need to withdraw your winnings from the casino account. The problem usually arises for those who are trying to withdraw a large amount and this attracts the attention of the casino administration.