Issues with the suspension's levelling and hardness on a Range Rover Sport L320 with a 3.6-liter V8 engine.

[BeardAndBeans]

Excuse me,
Since we disassembled the automobile, I've been dealing with this issue. Prior to it, the vehicle drove flawlessly straight and true, without any balancing problems whatsoever.
The U0155-87 error code was the most prominent of many issues that surfaced following the split. Once we were able to rebalance the car, the inaccuracy went away, but it's still not entirely level. The right side of the back of the vehicle is elevated above the remainder of the vehicle, and the back of the vehicle appears lifted in comparison to the front.

There is a constant whistling sound when I'm travelling at high speeds. The ride is fairly harsh, and the back end is incredibly springy. From time to time, I'll notice that the automobile is sitting with one side entirely raised and the other side totally dropped.
My previous attempts:
Depleting the air reservoir. Compressor replacement. Struggling to adjust the level (very difficult right now)

I would be eternally grateful for any insight you can provide as to the nature of the issue, its probable origins, or your own personal experience with a comparable situation. Fixing this has been an absolute nightmare.
Much obliged.

[Uneripty]

Which year model are you referring to? Could you please confirm if the Terrain Response dial has the Dynamic mode?

[BeardAndBeans]

To begin with, I apologise for the delay in responding. It is a 2007 model, and it does feature the highway emblem, if that is the dynamic mode you are referring to.

[Uneripty]

OK. If your dual-mode shock absorbers are linked incorrectly or damaged, they will automatically switch to the hard Dynamic mode, which is represented by the highway icon. Perhaps that is the cause of the severe suspension, thus it's something you should investigate.
You might want to check the alignment of your wheel level sensors in case that's the root of your levelling issues. When the vehicle is almost level, what does the 4x4 onto screen show? The four little red lights that each wheel on the screen displays. Where do they stand?

[BeardAndBeans]

The red and green indicators are almost in line, but they are never perfectly aligned; more recently, the vehicle has been leaning to the right while the left side is somewhat lowered. There is a slight tilt to the left side. As an alternative, it can be the other way around or have the back overly elevated. The highway icon is missing from the dial; I thought I had it. It does seem to be on the diagnosis tablet, which is confusing me.