M1 smart motorway cameras north of Luton

These cameras seem very flash happy. Not sure which junction it is but heading north close to the Lidl and Amazon warehouses on the left. A couple months ago I'm almost certain a camera flashed me doing a sat nav 70mph while no temp speed limit was in place. Still no fine to date, so I can only assume these cameras flash randomly for some reason. Watching the oncoming lane I'm always seeing them going off like a lightning storm too. Are they just defective or is there some other purpose to them doing this?