If the U channels are important to you and you can put up with less HD options for free to air channels you can reset to aerial mode if you have an aerial or you can switch between Freeview on your TV and the pro box.
The U app does offer the catch up app which is available through the pro box whether in IP or aerial mode.
If they ever come to IP mode for EE you could always reset back to internet mode for channels.
EE Pro TV box, Full Fibre 900
For EE contact details see
https://ee.co.uk/help/contact-ee
