If I go to Settings > General > About > Certificate Trust Settings... I see several profiles installed under the "ENABLE FULL TRUST FOR ROOT CERTIFICATES" heading.
There is a way to toggle them off, but not disable them.
According to this website, it says that you can remove these certificates by navigating to Settings > General > Profiles. When I navigate there, I don't see any corresponding Profiles that are installed. They seem to have been deleted a while ago, yet the Certificates remain under Certificate Trust Settings.
Another site recommends to re-install the profile temporarily and then remove it. However, the profile is long gone and I don't know where to get it from.
How do I remove these certificates that don't have corresponding profiles on my phone?