This sounds like a possible line or router issue. What happens if you move the router, via a new or known good microfilter, to the test socket? This is located behind the Master Socket's removable faceplate, if you have that type.
The TalkTalk Community has now moved to a peer-to-peer support model. This means that the TalkTalk team will no longer be here to support with queries. Don’t worry, there are plenty of ways to reach out if you need to speak to TalkTalk directly. For more details check out the link here How to contact TalkTalk Broadband - TalkTalk Help & Support
