Cant update from 10.15.4 to 10.15.6 or 7

I've tried about 10 times at least now - I click on update, it say its requires a restart, it restarts as normal, no change, nothing has updated!

Any ideas?

Thanks in advance

MacBook Pro (Retina, 15-inch, Late 2013)

2.3 GHz Quad-Core Intel Core i7