As an aside, I don't think they voted for Boris Johnson to take back sovereignty.
In these so called "red wall" seats (and elsewhere, but with less impact politically) people voted for Brexit for different reasons, but the point is they voted for it and unexpectedly that side won. Many may not ever have voted before for anything much less been on the winning side. And then it looked as if this small victory was going to be taken away from them: it reminds me a bit of the League of Gentlemen, and Geoff, Mike and Brian, the three mates, one of whom has had a pretty rotten time of it: he's especially jealous of Brian, who seems to have a perfect like, but Brian's mum dies before Geoff's does: "I won the mums" he says bitterly.
These people "won the mums" when it came to the refefendum, and irrespective of anything to do with soverignty (which quite honestly is cruel nonsense) they were damn sure it wasn't going to be taken from them.
And nor, in fairness, should it if possible.