Older versions of iPhone OS aren't new enough to have modern certificate authorities trusted, meaning only sites using older certificate authorities are able to have a secure connection.

Here are links to modern Certificate Authorities that may not be trusted on older devices (some other complications may prevent sites using these certificates from working, those can not be fixed by these.)

Dns Settings On Zte Mc888 Pro 5g [exclusive] -

: If web elements are failing to render, or if certain apps report network connection timeouts (a known issue with some streaming platforms on default 5G hubs), a manual DNS swap often resolves the conflict. Preparation: Choose a Reliable Public DNS Provider

: If you experience buffering issues with specific services like Netflix, resetting your DNS settings can often resolve the problem. DNS Settings on ZTE MC888 Pro 5G, How To - HardReset.info DNS Settings on ZTE MC888 Pro 5G