Welcome to the community and thank you for posting.
I am very sorry to hear you are experiencing an issue with your landline, we will do all we can to help.
Can you please confirm if your phone is connected to the Hub or the master socket?
Also, have you been able to test another handset to rule out an equipment issue?
Thank you for confirming.
Are you able to test another handset to rule out an equipment issue?
Also, could you please check that all cables leading to and from the equipment are secure and without damage?