Indeed, it has several design problems.
I had a major leak in the machine but it did not stop working.
After disassembly, I realized that it was the tank that was literally broken due to the pressure of the pump suction. Indeed, starway has not provided a draft of air in the cap. So for those who have this machine, I advise you to leave the cap slightly unscrewed in benefits.
After a short hack with another tank, it works again more beautiful!
Price ratio, speed and convenience is really not bad.