Joie i level isofix base - is it right?

Sorry I am not sure I understand your question. I hope this is a useful explanation.

The support leg of Joie seats tends to drop down to its most extended position when no pressure is put on it. This is a safety feature as it means even if you forget to install the leg, it should get itself into a supporting position rather than swinging loose. The buttons are to shorten the leg, rather than extend it.

When you install the base you should first connect the two isofix arms and check these are both green, then push the base back into the car seat so that it is as snug as possible. Finally, angle the leg towards the front of the car and press the buttons on the support leg in order to shorten it so that the base is in contact with the vehicle seat at the edge of the seat, the support leg is in contact with the car floor, and the indicator on the leg is green.

It's normal that the base can lift away from the vehicle seat, but you shouldn't do this because it will cause the leg to lengthen as you have noticed, and you will need to re-adjust it. The leg being too high makes the installation less secure, as well as making the angle of the seat potentially too steep for your child. You don't need to lift the base up when it's installed and it would not be subjected to this direction of force in a crash, so it's no problem and very normal (all isofix seat bases have this movement.)

Honestly on the Joie 360 we have the auto extending leg is the bane of my life as it will swing down and smack you in the shins when you try to change the seat between cars! Aaargh! But I can see why they did it that way