Firstly , can you try puttiong a blabk piece of paper under the easel , covering the centre with a large coin then exposing it , developing it etc.
Do you get a rich BLACK and a WHITE coin shadow ? This will prove that the light is working AND you have fresh developer .
If you produce good black and white then perhaps it may be in the Globe / the Styrene reflector or a VERY DIRTY LENS. Cheers