Solvent Delivery Issue

Setup:

Frankie's first run went smoothly. I pulled a full vac on the 30# recovery tank and put it on dry ice slurry while I assembled Frankie and moved things outside. I refreshed the vacuum just before I began the solvent wash.

Since this was the first run, the wash was with 5 cans of solvent (420 mil or 2.65 lbs.) and the material column dewaxing jacket had also been filled with dry ice slurry 45 min before the wash.​

recovered 2.2 lbs. of solvent into the 30# recovery tank. All good.​

Second run. Same setup with a 30# recovery tank on dry ice slurry....

The difference on this run is that i know the solvent tank is about one can short. So i went ahead and flushed one full can as before. When it was empty, i closed the valve and switched over to the recovery tank from the first run that has been sitting in the shed for a week or so. I opened the valve and heard the solvent flowing and verified flow through the sight glass. I also verified by watching the weight climb on the scales. ​

The problem:

Everything stopped after only just over 1 lb. of solvent had flowed from the solvent tank.
​

My Resolution:

I finished the run with 2 spare cans of solvent.
​

Lessons Learned:

What did I F* up?
What if any were my other options to restart the flow?​

Thanks in advance.