Interesting to note, when it's prompting you to trust your computer for the first time, it will say: Resetting Privacy settings on the iPhone deletes the trust relationship with a computer, so after resetting this, it will prompt you to trust your computer next time it is connected via the Lighting cable. Especially since they also can replicate it. This is all happening with completely new and old Apple's official Lighting cables, but none of my cables have wear and tear, so unlikely to be a physical connection issue.
They are still investigating, but they said they're unlikely to patch up older operating systems. So I'm not sure if it affects macOS Catalina, but I will be testing that shortly myself. I believe that they replicated this using the same operating system as the one running on my MacBook Pro (macOS Mojave 10.14.6). The Apple engineers have confirmed to me that they can replicate the trust dialog box issue when the iPhone's Personal Hotspot is enabled, and connected to a Mac using Apple's official USB-A to Lighting cable. I've been working with AppleCare on this issue for about 2-3 months now. To clean up from this - you may have to both update iOS / macOS and perform operations on /var/db/lockdown that are more complicated than removing a folder / file. NOTE: See the edit history if you're curious on updates / timing of this
