fibre broadband and wifi keeps dropping out

Hi,

Over the past few weeks, our broadband connection keeps dropping out. The red light appears on the router and it has to be re-started constantly. This happens very frequently throughout the day and night. Sometimes our wifi does not work whilst the internet light on the router remains green. 

We have replaced the microfilters and tested the phone line which appeared ok.

This is now very frustrating with having to constantly reset or restart the router.

Please help. Thank you.