That’s the case with an alert that can appear when an app or the operating system “Cannot Verify Server Identity” in iOS or iPadOS or “can’t verify the identity of the server” in macOS.

Android developers using third-party app stores will soon need their identity confirmed by Google. ...

Summary The “Cannot Verify Server Identity” error on your iPhone can be frustrating, but with the right approach, it’s usually easy to fix.

To correct the cannot verify server identity error, the first thing you should do is check that your iPhone is displaying the correct time and date and force quit the Mail application on your phone.

I haven't seen that dodgy ad for some time now, but as I'm getting messages that the identity of a server cannot be verified, it makes me wonder if this is related.