Fracino Contempo 2 - no flow for one group head

Swell6

Hi, this machine has sat for about 6 months, I fired it up and all is good except that there is no water flowing from the right hand group head. I’ve cleaned the top brass jet - which was blocked - but that didn’t fix it. I removed the group solenoid and tested it off the machine, and its working fine. However, there’s no water flowing from the water feed tube to the group head. There’s 2 tubes, an upper and a lower - not sure which is the feed to the group head?
With the group head removed, but the group solenoid connected electrically, when I press the start button, there’s a click from the group solenoid, and the pump starts running. I imagine that in theory water should flow from the open ended feed tube whenever the pump is activated? But there’s no water flowing even though the group head is not connected, and there’s just an open ended tube.
I notice on the schematic that there’s an inlet solenoid, does this get activated at the same time as the group head is activated? Or is this just to control the water level in the boiler?
Just to add, its a semi automatic machine so has a flow meter for each group head. There’s an orange light on top of each, the one for the working group head flickers when its flowing. The one for the non-working group head remains solid when activated - no flow so makes sense. Could this block water flow if faulty?
I’ve done lots of searches but can’t seem to find any definitive information to answer this question.
Any help with this would be greatly appreciated!!