Certain Vault locations are unvaultable by the Legion
Example of this in the clip.
I play a lot of Legion, I have found that many vault locations on many maps have this issue where they are unvaultable, this specifically happens for vaults where you end up falling from a high place. In the clip you see an example of it on the Gideon Meat Plant map, but I have also had this occur on Haddonfield, Crotus Prenn Asylum (Disturbed Ward), pretty much every Badham Preschool map variant, and Backwater Swamp (both variants). It is a very annoying bug that really ruins the flow of gameplay.