Ok, some more info.
At 3.11pm this afternoon radio playing on Echo Dot cut out for a couple of seconds - this is connected to Nova mesh which I use to boost wifi around the house. This is as expected but I also tested something else. I use Phone Link on my windows pc and can see when the connection is dropped at 3.11pm as a message appears. Today I switched off wifi (and bluetooth) on my phone before 3.11 came around and this time the connection was not dropped.
I've powered off the Hub 5 several times over the past few years and the 3.11pm issue has persisted. Everything looks fine in the back of the hub but the connection at the wall can only be accessed now by shifting a book case so not easy.
For info the following are connected into the rear of the hub:
Ethernet cable to Hive hub thing
Cable to Nova mesh box
Ethernet cable to PC
Cable to TP-Link 500 Mbps 2-Port Passthrough Powerline Adapter (connects to cctv recorder and feeds to xbox downstairs)
I also ran the Network Diagnostic tool and it found some issues but didn't say what
Your home network has a few problems.
Checking Broadband Service
Checking Telephone Service
Checking Ethernet Connections
Checking WiFi Connections
If you still think something is wrong, please check the following:
1
The temperature of your Hub 5 is normal.
2
Your broadband connection is working.
3
Gateway IPv4 address is valid.
4
Your broadband connection is ready.
There's a red triangle against Checking Ethernet Connections
Everything is working seemingly, the only irritating issue is the 3.11pm brief interruption in some things but not all. Am running the thinkbroadband tool as recommended.
Does any of this lot help?
By the way, I see some people suggesting that a pinched cable can cause RS errors (which persist) or possibly interference from a nearby device. I think the cable's ok but in the near vicinity of the Hub 5 is a CCTV DVR, an old smart tv which is never switched on, multiple power outlets, the TP Link mentioned above, usual household items. PC is about 4 feet away from Hub 5 (you can probably tell I'm clutching at straws now!)