The UKfreetv website doesn't show any ongoing engineering works in the North-East (except possibly at the Wall transmitter in Northumberland - but that only serves 5,500 homes):
https://ukfree.tv/maps/live
The BBC website is referring to the possibility of high atmospheric pressure adversely affecting the transmission of radio and TV signals:
https://www.bbc.co.uk/reception/works-warnings
That certainly seems to be the case around here, as reception of Classic FM on my car radio the other day was totally swamped by competing signals from France and Belgium. So the problems that you're experiencing might only be related to natural phenomena. (High pressure and/or high solar activity often cause disruption to radio and TV broadcasts for periods varying between a few hours and a few weeks. There's very little that can be done about it).