Thanks thetahsk,
That's quite strange but yes, it has something to do with one particular PC.
I compiled the app again on a different PC and, on that, it runs fine in any way: from IDE, from packaged EXE and from .bat debug file.
Then i moved the packaged, working app, on the previous PC and got the app deleted by the antivirus again...
I don't understand, maybe a false positive but with the same antivirus on both PC (windows defender) ? ?
Fortunately I can use the bat file to start it , the difference is the debug window.