Home sharing invisible on iPad and iPhone

I’ve got an iPad Pro, iPhone 15 pro, MacBook Air, and iMac, all with the latest updates installed. I’m signed in on all devices with the same I’d on the same network. Apple Music up and running on all devices.

I can see the home sharing on the macs from the iPad and iPhone, but NOT the iPhone or iPad home sharing. Ditto on one Mac to the other, and ditto no iPad or iPhone sharing visible from either Mac to either iOS device.

in effect, it’s as if neither the iPad nor the iPhone is sharing, but both are signed in under home sharing.

Be glad of any ideas as to how this can be sorted.