I'm having intermittent internet issues with my fibre connection at home. The devices remain connected to the router but there is "no internet". If I wait a while (1-2 minutes) then it usually fixes itself. Sometimes it may require my router to be reset. I can usually access my router's UI which confirms no internet. It happens often enough to be a nuisance and affects both devices on wifi and attached to the router via ethernet cable. 

My fibre line comes through the house through the roof space and a few years ago this had to be replaced as rodents had chewed through the fibre cable. My understanding however is that optical fibre is either all or nothing so my symptoms suggest this isn't the problem.

I'm thinking either it's my ISP or my router but don't want to go and change either unless I'm sure what the problem is.

My configuration:

ISP: My Republic

Router: TPLink Archer C2300

Thoughts?