I haven’t actually sent in a ticket but I’m sure someone else did ages ago, there was a thread about it somewhere and I mentioned the problem in the last release thread.
If you have a figure load in a hair then parent the hair to the head, drag and drop I the scene tab, then apply a preset pose the arms don’t pose.
Interesting. I had a similar problem with Filippa hair a while back—posted about it in the Members Forum. I don’t normally drag and drop hair, though; I just double clicked the preset in the Content Library. That said, Filippa was at that time a prop hair by default, so it basically did what you were talking about in a different way. It also occurred with some other hair, but I can’t remember what it was. (Filippa has since been revised to be a conforming hair, it seems.)
It also seems to be only an interaction with certain shapes at certain times, which makes it even weirder. With Filippa, I was using V6 with Zev0’s Growing Up.
All that said, even though Filippa has been revised to be conforming, when I try to load it onto the same G2F figure with the teenage shape from Zev0’s Growing Up, the hair doesn’t conform. When I manually make it fit with the Fit To in Parameters, I still have the same problem with frozen arms and shoulders.
EDIT: I did exactly as you described, and deleted the shoulder and collar bones from Filippa, then saved it out as a new product with a different name so I wouldn’t overwrite the old files. Then I loaded it on the same teenage shape that had experienced problems. Loaded in the right place and Fit To the character for the first time. Tried poses, and her arms were just fine. At least now I know how to fix it if I ever run across the other thing that gave me issues. For what it’s worth, when I saved Filippa out, it was set to be only a Follower, and not Follower > Hair, and it didn’t have a compatibility base. How much of that came as a result of the editing process itself, I don’t know. Anyway, it’s fine now.