Obviously, I was wrong, The service worker did not work and what I saw on the browsers application tab was not up to date. I had to unregister the service worker and refresh the page to identify this problem.
Anyway, I copied the older ngsw-config.json file and tailored it into the angular.json file (never had to touch this thing before) and now it is working fine.
Trying not to be lazy, I tried everything again and got the same results so maybe I was looking at a bug.
Also I looked for articles on the subject but all of them were old and at most referred to angular 6.
I hope this piece of information is helpful to anyone.