What can I do when line speed not hitting download guarantee speed
Both. This is a new installation. Now TV not hitting it guaranteed download speed.
How long have you been a customer for? Has it been over 10 days?
https://help.nowtv.com/article/why-does-my-broadband-speed-vary-in-the-first-ten-days
Could be a fault with the router or on your line. If it has been longer than 10 days give the team a call. Number in link below.
https://help.nowtv.com/article/how-to-submit-a-broadband-complaint1