Number plates don’t match what is in gov.uk mot checker site

[el romeral]

Out of curiosity, the last few days, I have checked the number plates on 4 UK cars which I have observed, in the MOT checker website. Two of them have come up with different cars from the ones the plates were on. One was a 5 series BMW and the site said 7 series. The other was a Bentley Bentayga on a 17 plate and the site said it was a Smart for 4!
I am in Marbella.
What is going on here?