Bubbles in my cup

No, you likely have a leak in the nozzle cap and tip, or possibly a deformed tip. Do you have a can of  Iwata lube? If not you may want to get one. It helps keep everything sealed up. You can also use wax as gaskets. Put some on the threads and base of the tip before assembly. And again on the needle from the taper back. Don't use too much pressure tightening or it can collapse the tip and deform it. You may need a new one. Check the tip under a magnifier and see if it is deformed. Hope it helps a bit.

Drew