TBF arming question

[Marabekm]

Morning.
I was building a mission, and put a flight of TBF Avengers in (AI). When I went to arming screen I noticed the Mk13(late) torpedo was grayed out and unselectable. I thought maybe it had something to do with date, so I changed that to a later one. (like the Bat Bomb). Still unselectable.

So what's up? Is there some secret I am missing to get the Mk(13) late on the TBF?

Version: 4.13.4