This guide will show you how to resolve the "Cannot Verify Server Identity" problem on the iPhone, we cover a wide range of tips to resolve it ...

Incorrect date and time settings can interfere with your iPhone’s ability to verify a server’s identity. SSL certificates rely on accurate date and time information to function correctly.

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.

While browsing using mobile safari (latest version of iOS) I keep getting constant popups 'cannot verify server identity'.