7i73 LCD shows rubisch

Just thought of something: how are you powering the OLED?

A LCD would be connected to the 7I73s VEE pin but this wont work with the OLED
Have you tried 5V and 3.3V power from the 7I73?

By the 5 V of the pin 28 and the GND pin 27. VEE not connected

I suspected the power supply and I checked
with an oscillo the power supply is clean

the funny thing is that when I send a fixed text
the oled sometimes returns an animated light of nignt club

An oled display is truly incomparable for a
industrial application: readability in all angles, contrast, time response etc ...

Did you try with 3.3V power?
If the display has CMOS level inputs (as opposed to TTL level)
3.3V signals and 5V power would be marginal

In my first message, I attached a link from the documentation
" voltage from 3.3 V to 5 V ". The test under arduino is with 5 V
it must not come from there

Are the Arduino signals 5V or 3.3V? (7I73 are 3.3V)

I just watched on the arduino (pro micro leonardo)
empty : 4.6 V
with load display LCD: 4.1 V
with load display OLED: 3.6 V !!!

it's not 5 V hum hum ...