No, it is not “normal”.
Don’t want to insult your intelligence
, but here is how I see it;
If you saw air bubbles (independant where you saw then at), it means there was pressure in the rail.
Pressure in the rail should be “fuel only”.
Air bubbles = fuel leaks = fire/explosion.
Even if you ran it and it did not start on fire, you will have lean running cylinders and blow the HG or something else.
Get it fixed!