I have 2 devices with iOS 12 and 14.
Both of them are configured the same way:
Certificate is downloaded from http://ipv4.fiddler:8866/
Certificate is installed from Settings > Profile Downloaded >DO_NOT_TRUST_FiddlerRoot
On the iOS 12 device all works like a charm - I can open HTTPS web sites in Safari and inspect the traffic. But on iOS device I get a warning "This Connection is Not Private", my certificate is not trusted and I can not ignore it by pressing "visit this website"
Any advice where to dig?