Neutral auction houses

[Suskis]

Today I tried to give 4 decent bags to my latest Ally alt in Booty Bay. I however wasn't able to buy or even bid the bags I put on auction with my Horde main: I kept receiving the message "you can'y bid on your own auctions".
However, I gave money to the very same alt in the very same way months ago: I sold a pumpkin for 1,000g in the neutral AH in Booty Bay and I bought it with my Horde main. Now, by doing the other way around (putting on auction cheap containers for my Ally alt to buy) I received that puzzling message.
What happened? Did they change how neutral auction houses work?

[Mitzen]

You used two accounts before, now you're trying it with one.

You can't buy auctions you posted from the same account.