Transfer BG from SHQ

[ShadowVillage]

I used to be able to transfer troop from my SHQ to other units stacked in the same hex. Now I'm getting a message saying "Source unit has 0 AP and did not move/attack this turn" and I'm no longer able to make the transfers. Is this a recent change and if so was it intentional? If not a change in the game, is there something I'm doing that's creating this problem?