Calibration Tools with Elegoo Neptune 2s

[HMRudi]

Hi
Since a while I am runnig Elegoo Neptune 2s printer with Optoprint. I wanted to test calibration tool especially for setting XYZ steps.
Elegoo has implemented a firmware wich is based on Marlin, but it is an elder version. and the neptune 2s is a "clone" of an ender 3.

Describe the bug
Reading xyz values from Calibration tools with M92 obviously does nothing.
Writing new values also brings no result.

Reading complete settings with M503 in a terminal window bings values:

N14401 M503*37
echo: G21 ; Units in mm

echo:Filament settings: Disabled
echo: M200 D3.00
echo: M200 T1 D3.00
echo: M200 D0
echo:Steps per unit:
echo: M92 X80.00 Y80.00 Z400.00
echo: M92 T0 E137.35
M92 T1 E133.00
echo:Maximum feedrates (units/s):
echo: M203 X500.00 Y500.00 Z10.00
echo: M203 T0 E60.00
:

So the values are there...
Calculating new values by hand should be
X: 83.33
Y: 80.12
Z 400.0

Writing the values into the terminal window, new values are excepted by the firmware.

M92 X83.33 Y80.12 Z400.00
M500

Putting new values into the mask of calibration tools I got an red error from printer firmware in Octoprint

Versions:

• OctoPrint version[e.g. 1.7.3]:
• Browser FireFox:
• Printer type: Elegoo neptune 2s
• Printer firmware [displayed message in M115 command]: no response...