My transmitter is Billsdale but my Freeview HD box picks up Made In Tyne & Wear.I'm using a indoor aerial with a build in booster.I pick up all HD & SD channels with no pixels when watching any channel.I think the local multiplex is using low power.When my Freeview HD box has finished the rescan there's a option to change the region but there is only Newcastle is there & no Teesside region option.
You may need to manually tune your receiver instead so that it avoids scanning the Newcastle local mux instead.
If it receives both local muxes, you may get Made in Teesside in the 800s.
Run a manual scan on UHF Ch 24, that's where you'll find it. However the beam from Bilsdale is very narrow, unless you're inside it, your chances of reception are slim ( particularly using an indoor aerial )