Recent car sagging from the front?

Hello.

I have my vehicle listed above summit model repaired at a mechanic a time ago, who replaced both of the front upper control arms, unfortunately my air suspension had some issues thereafter, which he could not solve them until I did some searches and I had to fix the problem myself by tightening the bolts only when the car is on the ground not when it is actually jacked, since I did the repair, I started to hear hissing sounds from the compressor l, like an air is escaping under pressure or like when we hear the sound of air hissing from a lorry !
but there was not any issue with the jeep apart from frequent finding of air compressor working at morning, until now there was nothing annoyed me so much,
Recently and actually 4 or 5 days ago, I started to find the jeep sagging from the front when kept overnight until the morning, but it corrects itself when I just start the vehicle.

I think it is a leak problem and seems like a small leak that it needs an overnight to become evident.

sorry for being too much talking, but I wanted you to be fully informed about the problem.
I hope you can help me with where to start and what are my next steps, please. Thanks, a lot.

I will leave a video of the compressor strange sounds for you.