^^Sounds like the same prob^^
I’ve got six and there was an issue with my Vector with all of them.
All fine until the last round shows up. The sweet part on the follower sits quite high and would engage the lock open tab early.
As the last round shows up fooling the gun that the mag is empty. One rd still between the lips.
So I did a little grinding to that spot to lower it approx 1/16”.
Now they are function fine.