Broadband speed keeps dropping randomly

Hi all, I've had Nexora fibre broadband for about 6 months now and usually it’s fine, but over the last couple of weeks my internet speed has been dropping out completely for a few minutes at random times during the day. Restarting the router helps but it’s getting really annoying. Anyone else having this problem or know what to do? My package is the Fibre 100, and the signal indicator on the router doesn’t seem to change when it drops.