What does the Fuel Tank Bleeder Valve actually do?

[Jeffd]

2000 Boxster S with difficulty adding fuel. Intermittent P1128 and "coke bottle" sound from the filler neck. When I trip the flapper reed switch I can hear/feel the electrical valve at the top of the fender click.

Does anyone know how to test the Fuel Tank Bleeder valve? What does it do besides being a holder for the flapper reed switch? It seems to have no solenoid or electrical component besides a ground strap.

If I disconnect the hoses from it I can fill up my tank. If I reconnect them I cannot fill up my tank. I can blow air through it, and I can blow air through the vent line that goes from it to the top of the fuel sender. If it's allowing air through it from the black fitting to the orange fitting is that normal behavior? It may be restricting the airflow some but it's hard to tell.