Happened earlier today, I auto-attacked before Osiris' spawn animation happened, and got stuck laying down until i attacked something. I could still walk around and attack, but if I hit nothing, I would just go back to laying down. I tried it with Geb in a practice and it worked this him as well, so I don't know how many other people can do it. It's more of a funny bug than a serious bug, but a bug nonetheless.