Are you still having this issue? I thought i was having the same problem, then when I googled it, and was reading this, suddenly I heard the money sound and looked up to find it had sold the stack finally. I'd restarted the game 4 time thinking it had been frozen, but clearly I was just impatient. It does completely freeze but then eventually if you do nothing and wait, it seems to sell it and go back to normal.
I really hope this is the case because I'm just coming back to the game after finding out they finally added that feature because for some reason I have a stack of over 200 basil and same with other spices that for some reason went into my house inventory and I didn't know until it was too late and got sick of selling it one by one
