Volvo i-shift problem

Hello, please help me find the problem with my 2017 Volvo i-shift.
The code i get is SA 24 DTC p107538
The truck been at Volvo Dealer and they can't find the problem and told me we need to take the transmission out to open it and look inside. They think it's the clutch.
I have a feeling it's something else and didn't Approve to take the transmission out.

So the i-shift works weird only when i get the Check Engine light and on the Dash the message - Check Transmission System at next Stop.
Like today when i start the truck there was no Code and Transmition worked like Supposed to, no problems.
The code comes On Always when i come to Red Traffic light, i stop, the truck is in Drive and after 2-3 sec i get this Check Message and Transmission start working weird.
If i come to Traffic light and put the truck into Neutral and wait for green light, then Drive! i never receive the Check and everything works fine.

So now whats wrong when this code is ON!
At traffic light when i get Green Traffic light i release the foot brake truck start rolling back as it would be in Neutral, then i Accelerate only then i start feeling how i-shift start moving the gears and putting the truck into Drive and it start driving! And it works perfect , shifts perfect, Everything is like suppose to be!
Only this Start part and also my PTO is not working unless i accelerate. I use PTO for my Car Hauler Hydraulic system.

So basically the transmission is only working only when i accelerate or have speed, if the Check is ON.
Sometimes the code goes off and everything works perfect, truck doesn't roll back, PTO works.

I have a feeling it's something related to the Air Pressure, it's like not getting the right pressure or some Valve.