Had this happen during a game today. I played a minion during the shop phase, tried to sell it, and got the “Minions can’t attack the turn they are played” message. Immediately rebooted, happened again. Sold another minion that had already been on my board, tried to cycle one from my hand, got the same message.
It didn’t persist into the next round thankfully but it definitely threw off that shop round for me.
Playing on Windows PC desktop client.