Hello ilguargua,
I have uninstall the arduino-ide 1.18 (sudo apt autoremove arduino).
Removed all the file in /etc/apparmor. with a référence to arduino and also to /home/michel/Arduino.
Reload the PC.
Copy the appImage of the arduino-ide to the same directory of your,
Create the file usr.local.bin/arduino in the /etc/apparmor.d with the same contents.....
Reload the PC.
And now the ide 2.3.4 work........ 
Still a problem, but not really important I have no link to start the ide from the desktop...
I'll doing that after
A very big thanks at everybody for your help
m-sem