I thought so, I got 3 flights yesterday. First flight was mild flight and I had a lot of air inside of my UAT once on ground with 1/4 fuel left in both main tanks,

2nd flight was more aggressive and it the UAT was almost 1/2 empty but not sucked in like before. Could not find any leaks or restrictions

So 3rd flight was very boarding, Flew flat and level for the whole flight no loops or splits S and only went to Full power 2 times for a few sec, and it was 1/4 full of air.

I don't see air bubbles when defueling, or when using the pump with the controller.

I pulled the UAT apart last night and the filter is very clean, I did add a bigger vent adapter that goes throw the bottom of the fuse for more vent airflow so I'm not sure if that will help things I'm gong to fly it again today to see.

I was thinking of Connecting an air compressor to the fill line and fill the whole fuel system at 10psi or so and spray with Windex to look for leeks, What do you think? The main tanks are plastic, so Im not so worried about blowing up a tank.