My washing machine is connected to a dedicated tiny wall tap (whose wall is in fact an empty space which can be accessed), which in turn is connected via a flexible internal pipe to a divider, and then to the main valve which serve the whole bathroom.
Recently, the pressure have been lower, and even more recently, the flow stopped completely. All the other faucets are working fine.
The most weird thing, is that if I reduce the maximum flow a lot (to around 0.07 l/s) from the main valve, then it works. Any little amount of pressure more, and it stops. Note that it has hysteresis: I need to relieve the pressure almost completely for it to resume.
This is true even when the washing machine is disconnected and there is nothing after the tap.
What could make a tap work in a so bizarre way?