Focusrite Scarlett Solo USB interface not recognised by iPhone

I have an iPhone 14 on iOS 18.1.1 and I'm having trouble with it not recognising my Scarlett Solo USB interface. I have a Tendak 3.0 powered usb hub and the Apple camera adapter, and it was all working a few months ago, but now when I hook everything up and plug it into the phone I get nothing. GarageBand doesn't recognise that anything has been plugged in and I get no prompts to use the interface. I've seen online that sometimes iPhones will read USB interfaces as storage devices, and I have had a bit of trouble with that before, but I was able to fix it by returning the USB interface to it's default settings and re-plugging it in... this is not fixing the problem now. I have an older iPad (iOS 16) that also won't recognise it. The interface is fine, it works perfectly on my Mac Mini, but I need it working on something portable. I've tried different cables, but I don't have other powered USB hubs or camera adapters to check those. Hoping someone can help, or knows what I might be doing wrong?