Flight Crew Air Transport Pilot (ATP)
Communication Breakdown; Confusion
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Ground Equipment Issue
Flight Crew Overcame Equipment Problem
Human Factors; Airport; Company Policy
Taxiing into the gate; the visual docking system was reading STOP" but the marshallers were continuing to wave us in.  Stopped and called OPS who said they were looking into it.  Marshallers continued to wave us in.  Had to call OPS again; who said they weren't sure if it was working.  We advised them to turn the system off so we were not receiving conflicting information; and after several minutes of all the marshallers trying to wave us in; one of them finally went over and reset/turned off the system.  We discussed the situation; and being good daylight visibility; taxied in using the marshallers only. This is not the first time I've had conflicting information between ground crew and the system; usually with the display advising "STOP".  I am not Seattle based so don't see the system every day but I have used it fairly often; and I think we are just setting ourselves up for potential issues if we get in the habit of not trusting or ignoring the system sometimes and relying on it other times.  The system should either be working and used or completely off when we're relying on marshallers."
During taxi into the gate; airline pilot reported receiving conflicting directions from the marshaller and the automated docking system.