Why are you assuming it is the "build"?
1. Which LNB do you have? Is it a a wideband LNB for Sky Q?
Edit: If unsure, take a picture of it and upload to the forum.
2. Does Tuner A have a signal wire?
3. What have you set Tuner A as in tuner config?
4. Does Tuner B have a signal wire?
5. What have you set tuner B as in tuner config?
6. Post a picture of the scanning options you have used.