Silicone filled air brick?

I do believe that this would not affect the house as it was only two mini holes Blocked and I do believe that sky and virgin run the cables through Air Bricks sometimes and the silicon is just to hold the wire in place

All air brick should be clear and flowing as this allow moisture to be removed from the house and they all placed in correct place

They normally silicone the vents when they installed expanded polystyrene bead insulation. That's to stop any bead coming out. But if you have had bead installed then they should of unblocked your vents once the bead had been glued, that way you will still have air flow in your cavity. If any other insulation has been installed then it shouldn't have been blocked with silicone.

Sometimes bt/virgin etc run cables and may of used this if it is silicone to hold in please as an adhesive.

But answer is no air bricks are installed for a reason filled may aswell not be present.

Below dpc allows air flow so timbers etc can breath and prevent rots and other moisture problems occuring.

Same as above it's all about controlling the air flow to prevent condensation problems etc