washers working intermittently

Hi,
We had a problem with our washer pump leaking so I replaced the pump and motor.
At first it worked fine but now when you try to wash the front windscreen it does a little squirt then comes out the rear.
The rear works perfectly, its the front that's the problem.
I removed the hose at a joiner near the rear corner of the hood and when you activate the washers is pulses for a second then pumps fine.
I think the pulsing is the problem but I'm not sure why. Maybe there is a non return valve or something not sure.
Any help would be great on how it works from front to rear, I just can't get my head around it.
I believe the pump goes one way for front and the other way for rear, but why does it try to come out the front then change to the rear?
2016 model.

Thanks in advance,

Tez.