Toilets, Sinks, Showers, Tubs and Disposals - New Kohler toilet - fill valve won't work

Took out old toilet, installed Kohler Wellworth K-11473-0 model. Everything went fine, but toilet reservoir won't fill. Water source to toilet/fill valve connection is okay, water is flowing from source, but doesn't come out of fill valve unless I take top off reservoir, reach in, and apply significant manual pressure on the large cyclinder thing that is on the fill valve post (laymen here). If I do that, it slowly fills. But the second I stop applying pressure with my hands, the water flow immediately stops. Am I missing something? Or faulty fill valve component? Thanks for any advice.

There may be some debris in the valve, or you could have a bad valve. If I recall, they use the Fluidmaster fill valve. Turn off the water rotate the top black platic cap 1/4 turn CCW, it should lift off. Remove the washer, slowly turn on the water keeping your hand over the top of the valve(water will spurt). That should clear anything that might be there. Reassemble and try it.