Yesterday I noticed problems with broadband whilst I was installing a Ubiquiti Dream machine (UDM) and reconfiguring my Hub3 to Modem mode. When contacting phoning VM there was a recorded message saying work was going in in my specific postcode HD33XU until 3 pm and there would be broadband issues.
Shortly afterwards I was able to complete the configuration, the UDM saw internet speed of 110Mbps download and over 10Mbps upload. Broadband has seemed to be continuous since then.
A check on my Internet Check Speed this morning shows that after broadband was restored the speed dropped significantly to around 80Mbps.
This is the second time there has been a step change from 100 to 80Mbps, the last was Sept 2020, as I recall.
It is as though whenever work is done it is pot luck whether you get a slow reconnection or a full-speed one!