Traffic Lights timing incorrect

Timing on traffic lights for the Gatwick spur roundabout have been incorrect for a few weeks now which is causing a backlog of cars on the roundabout. Previously cars joining the roundabout from the M23 South would be released and traffic lights would be green until exiting onto the Gatwick spur this is not happening now and cars are stuck on the bridge and blocking the roundabout in all directions and long queues are forming on the m23s junction