Speed camera flashing although going under speed limit.

There has been road works going on for a while on the A14 after J37. For a while speed limit was 50 and there is a speed camera placed as well. Just few days ago the speed limit was reduced to 40. Today I saw that there was the national speed limit sign placed maybe couple of hundred metres before the speed camera (which has been put on 50mph for the duration of these road works). However, the camera has been flashing drivers who follow the national speed limit sign. They should remove camera from there or change the setting to 70mph. All drivers who have been flashed in this period of time should not get penalty points.