iTunes on Windows 10/11 PC will not recognise iPhone 15 when connected by USB-C
iTunes was not detecting iPhone 15 devices when the Apple-issued USB-C to USB-C cable was in use, so I had switched to the Apple Devices app, as this was detecting iPhone 15 devices when the Apple-issued USB-C to USB-C cable was in use. However I purchased both a generic USB-C to USB-A data cable AND a USB-C Socket to USB-A Plug Adaptor (thankfully my non-Apple PC still has USB-A ports), and when using either, iTunes was now able to detect the iPhone 15 and update/restore/DFU to iOS 18.1 via ipsw file works without issue. So it appears iTunes cannot recognise devices connected via the Apple-issued USB-C to USB-C cable (or perhaps USB-C to USB-C cables generally, although it can detect earlier devices connected via Lighting to USB-C cable), at least with my PC under both Windows 11 and Windows 10 before that.
Hope this helps somebody :)