No mobile data (after latest security update?)

This morning I installed the latest security update (dated June 5th 2022) on my FP3, that runs Android 11.
But now mobile data isn’t working anymore.
It says 3G, but I don’t get an internet connection.

Mobile data worked just fine
WiFi works fine.
Restarting the phone didn’t help.

Has anyone experienced the same problem?

Please have a look at this for a potential fix – and if necessary, follow up there, please: