Broadband keeps dropping - BT says no fault

[Rotarua674]

Have fibre to cabinet and broadband has been stable for years.  For last 6 weeks we get broadband dropping completely at the router (blue light changes to flashing orange).  Outage lasts between 3 and 7 minutes before returning.  Of course this knocks all devices and services off and need to be brought back onto the WiFi.  Broadband speed needs to build back up after each outage.  BT line checks say no fault on the line.  The BT wait time for a call to be answered mean it’s impossible to speak to BT and get line tested during the outage.  Happens differently times of day with no pattern.  Only thing I can think of is there are 100+ houses being built nearby with the road dug up repeatedly next to the site and a few hundred meters from house.  Outside of these outages - one every few days - broadband is stable.

Any suggestions or ideas gratefully received.  Thanks.

[imjolly]

if you have a home phone and not digital voice have you tried checking your line for any noise which could cause drop in connection

could there be any electrical interference near hub say from christmas tree lights