2012 westernstar 4900, washer squirter works on drivers side, not passengers anymore, both hoses run

Both hoses run to tank, one goes into top of tank, the other to the pump, with only one comming from tank on bottom side to pump, can somebody please exsplain to me how that works? Makes no sense

 

Most windshield washers whether car or truck have one hose from the reservoir/pump that feeds into a tee (#3 circled in blue). From the tee the fluid gets fed to both the driver's and passenger side of the windshield through the nozzles (#1). You are saying that the passenger side used to work and just stopped working and no one worked on the washer system? A pic is always helpful.