My friend and I recently played Halo CE: Anniversary on MCC and had a weird bug in campaign. We were playing through Pillar of Autumn on Heroic difficulty (no mods) when my friend picked up a pulse rifle and could no longer pick up any other weapon. It only showed for pickup of the pulse rifle. It wasn’t until I killed them to respawn that they got the ability to pick up and switch weapons. It’s like not a game breaking bug, but can be annoying. It hasn’t happened again so far.
Thanks.