I have the problem with my CP88 in Cubase when i change the volume in Daw the CP pulls all Volumes in a layered sound on the same level . Can you fix this by the next OS update?please and best regards from JP

There is nothing really to fix. Maybe this will help.

When recording the CP88 to a DAW, like Cubase, the three Sections are addressed on a single MIDI Channel. This means if you address it with a Channel message, like cc7, then quite naturally all Sections jump to the same Volume level — anything set to receive on that channel will exhibit the same absolute level.
This also means if you address it with a Channel message, like cc11 Expression, then each Section will change output level but remain proportional to the others. (A Section can be set to ignore cc11, if you desire).

These two Control Change messages are universal throughout MIDI.

Each CP88 Section, has its own Volume controlled by a specific cc number of its own. If you wish to control the individual Volume of each Section within a LIVE SET use the Section’s “Volume” Knob to manipulate the level. This can be recorded real-time or overdubbed to Cubase, as you require.

You don’t really specify exactly how you are changing the Volume in the DAW but if you are sending cc7 then expect all Sections to jump to the same value — as mandated by the MIDI spec. If you are using cc11 (as the Foot Controller 1 defaults) you can control the relative Volume of your Sections and record that to Cubase. Use an FC7 connect to the Foot Controller 1 jack to control all Sections simultaneously x in relative proportion to each other.

For individual control (use the following cc# on the MIDI Channel you are using for the CP88)
Piano Section Volume cc13
E.Piano Section Volume cc19
Sub Section Volume cc30

Hope that helps.