Hi guy's

Just wondering if it is possible for air pockets to get trapped in the lower fork legs or if it eventually rises to the top through fork movement?

Replaced my Street bob front fork springs with the Progressive drop-in kit but found it had only 20mm up travel. I then removed/drained and refilled each leg with 600ml as opposed to 850ml as per manual. That gave me back my 120mm total travel but after the first ride of 50klm or so the travel has dropped back to about 105.

I did not pump the forks after refilling with oil prior to refitting springs and putting on fork cap.

Thinking i may have trapped air under oil at bottom that  can't find it's way to the top?

Stuck for ideas otherwise.