Same problem here. I got 5 dev devices. All with iOS 18.0.1 dont get their symbols copied (stuck at various percentages, even after hours). iOS 17.x devices work without problems. macOS 15.0.1, Xcode 16.0. A real nasty problem! 15.0.1 didnt do it for me. Deleting DerivedData or iOS DeviceSupport doesnt help. Other solutions like putting device into flightmode and enforce usb doesnt help either...

Turns out it was a problem with the nib file, which was not a problem for the "old way" of registering nibs. I recreated a new swift class + xib file and then it worked. Couldn't see what the difference was though...