As per my post above, I have the same problem as OP.
Except I did go up to 60 psi with fully opened needle valve and I then switched over to in tank diffuser that works.
To me, the atomizer is clearly acting as a road block.
Btw, I have 2 other identical atomizers except for the 5/8" size. One is working and another in storage.
Courtesy * Integrity * Perseverance * Indominable Spirit * and Self Control
Tenets of TKD