The problem consists in an overabundance GUM on the form - it is necessary to check pressure between GUM shaft on development or to try to reduce submission GUM or in general to disconnect submission (only for check).
It is possible to try clean off GUM by the printed machine.
If the problem was not solved, it is necessary to check up humidifying by the printed machine.
Here still the moment, has forgotten. It is necessary to check up blank space on the form, probably brushes in developer badly rub the form and polymer is badly washed away (are dirtied or backlashes)