Ken,
You mentioning that you do 30 minute boils reminds me... I was doing 30 minute boils for much of the year in 2020. I would do 5 gallon batches, use a floating dip tube and biofine, but always always always, the last about 1/2 gallon would be hazy. HAZY! That's how I knew the beer was almost gone. I chalked it up to the chill haze settling out, but not completely. I never really found an explanation for it. The beer would be CLEAR until that last 1/2 gallon.
And if I used a regular dip tube, the beer was hazy throughout the life of the keg. I really do thing 30 vs 60 minute boil length matters in terms of clarity. It gives the proteins more time to coagulate and when I switched back to 60 minute boils, my issue went away (unless I lifted the keg to check how much was left, which I've since stopped doing).