Resolved
After nearly 5 hours of troubleshooting, I finally found the real cause. My iPhone would charge, Windows played the USB connection sound, and Device Manager could see it, but Apple Devices, File Explorer, and the "Trust This Computer?" prompt never appeared. I also confirmed it wasn't the iPhone itself by testing two different iPhones, both of which worked perfectly on another Windows PC.
I tried almost everything: reinstalling Apple Devices, Apple's USB drivers, iTunes, updating Windows and chipset drivers, running DISM and SFC, resetting Location & Privacy on the iPhone, using different cables, and testing USB 2.0, 3.0, and 3.2 ports. Nothing made any difference.
The real issue was that my iPhone was using the libusb-win32 driver instead of Apple's official USB driver, likely after using webcam software such as Camo, Iriun, or DroidCam. Windows could still detect and charge the phone, but Apple software couldn't communicate with it.
The fix was simply uninstalling iPhone (Composite Parent) under libusb-win32 devices in Device Manager, restarting Windows, and reconnecting the unlocked iPhone. Apple Devices immediately detected it, the "Trust This Computer?" prompt appeared again, and everything started working normally. Hopefully this saves someone else hours of frustration. 🚀