Long time lurker, first time poster.

I just wrote up the whole history of this problem and it ended up being a 3 page Word doc, so I figured I'd start with the basics and give more info when/if it's asked for.

Nuova Simonelli Aurelia volumetric 2-group has been overfilling and blowing the safety valve the past 2 weeks.  The problem is intermittent, sometimes the autofill shuts off just fine, sometimes it just keeps going, and I think sometimes it starts filling on its own without the autofill cycle even starting up (can't be sure about that though)

Checked autofill probe, was fine, replaced anyway.

Checked inlet solenoid, seemed good, replaced inlet solenoid, rechecked inlet solenoid, seems good.

Repair shop said main board was fine.

Repair shop replaced brew buttons on right group, thinking that a janky taped-on button was messing with the electronics somehow.

Replaced safety valve just in case.

Stripped power cable and reconnected plug to be sure there's not a ground issue.

The boiler is still overfilling and burping from the safety valve.

Myself, the cafe owner, 2 trusted repair guys with a lot of experience, and the support people at NS are just about out of ideas.  Little help?  What would you try next?