From checking your local area I can see that the mast closest to your property (post code) is currently offline which may explain the poor signal. Other masts local to you aren't reporting any issues but this may mean that if it is a built up area you're trying to connect to a mast further away that will be servicing more users causing congestion.
If you have the opportunity, please try this in another location to see if the issue persists. For reference, masts in the WV6 area are all operational at this time so may be a place to test this.
Rob