Is it the BT Set top box that you've got ? Mine has the Discovery+ app on it and I'm able to view TNT Sports through that.
Did you get any contact as @DarrenDev suggested would happen?
IPC6023 is usually associated with failure of the network to provide the box with the multicast signal it requires. I'd suggest buying a long ethernet cable for a few pounds to replace the adapters, just to eliminate them.
The DIscovery+ app is only available on the Pro Box at the moment. If you have one of those then you could try connecting by WiFi instead of ethernet or adapters.
no nobody contacted, thank you for all the information, im giving up im afraid as the set up we currently have doesnt seem to work with the set top box anymore - thankyou again