RSP-1576MKII - iPhone connected to front usb input - no sound - SOLVED

[Jazzy16]

I am testing the inputs on my new RSP-1576MKII. When I connect my iPhone XS, IOS 14.4.1 to the front USB Input of the processor, I get no sound. The input is configured correctly and it recognizes the iPhone as connected. In the AirPlay display for the iPhone's Music app, the speakers indicated are "Dock Connector", which is correct I believe. Interestingly, the volume slider in the Airplay display are greyed out.

Anyone familiar with this issue?

[Jazzy16]

I'm still trouble shooting this but I now think it may be related to my use of a HomePod Mini. Connecting my iPhone to the front USB input of the processor wasn't changing the iPhone's connected speaker from my HomePod Mini to the Dock Connector. Rebooting my iPhone may have fixed this. In any case, I now make a point of switching my iPhone's speaker from my HomePod Mini to the iPhone before connecting to the front USB input of the RSP-1567MKII.