I have found several bugs, I'm playing on PS4.
First, the legendary animal trophies don't show at the longhouse. I have killed the Elk, the Black Shulk and the Corpse eaters, I have given all three to Wallace and only the Corpse eater head is showing.
Second, the berserker Bjorn who you recruit in the exclusive mission of the ultimate pack, always gets automatically out of the crew and changed with another crew memeber when I select it and fast travel. And also when selecting it it looks like a different character. My game has even crashed sometimes when selecting it.
Also I don't know if it's intended but characters you recruit in story use their own wood shield instead of the crew one, if it's intended I don't get why buying shields from the store if half of the crew is not going to use them.