Freeview Tuner doesn't show Freeview channels

[SkyFan]

Because I want ITV London, etc. My Postcode is DG1 4DJ. That page says I should use Caldbeck. Is that correct?

I installed my Sundtek USB tuner.

Setup > Tuner Config > Tuner Setup > Select Tuner E: Sundtek DVB-T2 (III).

Tuner Type: DVB-T2
Configuration Mode: Enabled
Country: UK
Region: Change to "United Kingdom, all regions Europe DVB-T/T2)". Also tried Calbeck, Cumbria.
Enable 5V for active antenna: Off
Press Green to Save.

Menu > Setup > Tuner Config > Terrestrial Scan.
Band; UHF Europe
Network Scan: No
Clear before scan: Yes
Only Free Scan: No
Restrict Search to Single ONID: No
Create Terrestrial Bouquet: Yes
Create Terrestrial.xml file: No
Tuner D: Sundtek DVB-T2 (III) (1/0) (USB) (DVB-T2)

Tried it with UK all regions as the region. HD channels didn't appear with same problems as before. Tried it with Calbeck, Cumbria and HD channels still don't appear in Favourites > Terrestrial.
However the HD channels appear in Providers > Unknown. I'm getting a picture now but there's picture breakup every minute or so on all the freeview HD channels. When I press OK on a channel to view info about the channel it says "DVB-T and HbbTV" for BBC 1 HD and BBC 2 HD.

The following channels say DVB-T and do NOT say HbbTV and haven't seen any breakup on them yet:

Channel 4 HD
Channel 5 HD
ITV HD

The following Standard Definition channels say DVB-T and do NOT say HbbTV and have a lot of breakup all the time:
Dave
Drama
Sky News
Yesterday

Above are just some examples, I haven't checked all the other channels as I'm not interested in them.

I enabled service type icons. All channels in Unknown and in Favourites > Terrestrial have a blue tower picture to the left of the channels names.

Anybody got any idea of what's going on here? When I plug the aerial directly into my box's tuner I don't get a picture on any Freeview channels as there's massive breakup and didn't get HD channels at all. When I used the Sundtek tuner I got the HD channels and the HD channels show but have break up every minute or so and the SD channels have a lot of break up.

Is there a test I can do to check that I'm able to receive freeview properly? Don't understand why not even the USB tuner isn't working properly. I used to use that tuner on my VU+ Duo 2 box in the same room.