One problem at MAN was the mix of lo-cost and full service airlines particularly on T3. The lo-cos refused to pay for air bridges so some were removed, the remainder were poorly maintained or broken and out of service and amongst the handling agents, there were never enough qualified bridge drivers. Last minute changes for full fare airlines wanting bridges meant there was always chaos with busses and steps blocking the aprons. The loco's developed a habit of holding a whole aircraft's worth of pax in the stand stairwells which was almost certainly a H&S / fire hazard and of course they wouldn't pay for enough gate staff so these herds of passengers often ended up released into the wild and randomly wandering around on the apron with very little supervision. Another safety hazard that was regularly reported but the CAA and MAG didn't seem interested so long as hundreds of cones and barriers were sprinkled around.
One way to fix MAN would be to introduce consistency and either scrap bridges across the board or get them all fixed up and working properly with enough qualified drivers and force Lo-cos to pay for and use them.