I'm in Leeds LS17, and after a year of good internet connection the last few days my router keeps disconnecting from the internet. Same as you, I just get a flashing arrow.
Turing the router off/on doesn't seem to resolve the problem, the only solution currently is to unscrew the coaxial cable from the router take it out and then reattach it. The router then reconnects .... but after a few hours it drops the connection again.
Still getting daily (if not more) disconnections that are only resolved by removing the cable from the back of the router and reconnecting it. Turning the router off and back on again doesn't seem to resolve the issue.
I can see from the log that I'm getting a lot of 'No Ranging Response received - T3 time-out' errors.