You may have already tried this. Disassemble the tan nozzle. There are three pieces. Nozzle body, inner nozzle sleeve and needle/spring. Clean all parts especially the inner nozzle sleeve. Paint can build up inside. Typically if the nozzle does not spray at all it is because the needle is stuck in the inner sleeve.
As for the red tip spitting and bubbling back in the cup, this usually means the nozzle is not tight enough.
Hope this helps.