Electronic speed signs malfunctioning

(Not sure if this went though the first time)

Between junction 3 and 4 on the M2 and possibly further back towards junction 2, the electronic temporary speed signs have been constantly displaying 40 every time I pass them for the past 2 weeks for no apparent reason. I've noticed this problem a lot in the past but not as consistent as recently.

This occurs when there is a normal level of traffic, no accidents, broken down vehicles or any other obvious reason. Also further down from junction 2, random lanes will have a 40 speed limit set but others don't which seems nonsensical.

The problem is that literally everyone ignores these signs and drives at normal motorway speeds, presumably under the assumption that they are faulty, which is potentially very dangerous when there is a legitimate reason for a reduced speed limit and nobody obeys it or if someone does decide to drive at the speed indicated by the signs in one of the middle lanes while everyone else around them is driving twice their speed.

I'm assuming the control system for the signs are broken or whoever is controlling them has no idea what they're doing.