@Christopher_G A surprisingly positive update. It's managed to fix itself.
The issue had been occurring since Friday 16th up until last night. Yesterday I performed some more tests by changing multiple different combinations of cables from the fibre to the hub, hub to the laptop, none of which worked. I then reverted back to the same cable combination since before Friday and double checked, still no joy. In fact, by this point, it hadn't deteriorated even further down to an upload speed of 0.2 Mbp/s (download speed still unfazed).
We then went out last night and returned with the router showing a yellow ring - no internet connection then almost immediately back to the green ring (without me touching anything). This then happened again almost half an hour later only this time, everything was completely back to normal, with a download speed of 499 Mbp/s and an upload of 71.9 Mbp/s. This is what's baffling as nothing else my end had changed (and still working fine now). I've also checked the firmware version, nothing has changed.
Therefore I have 1 of 2 conclusions. Either some work was carried out at the cabinet over the road (not seen anyone for weeks) or something was change on the account as it almost felt like we were being capped/throttled.
It would be great if someone has come across this before and could shed some light on it or whether it's just a mystery and solved itself.
Thanks
