Ok After some trials, I found this issue and leave the solution here in case someone run into the same problem :
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The project contains different successive maps, you have to ensure that in the project settings default map (game and editor) are set to your very first map in the list (usually your intro or logo)
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At package for oculus mobile devices, add an array and choose Quest
Doing this solve the issue, the launching works correctly.
Also a remark : with the Quest it seems you use launch for packaging (and not files–>package) with Unreal.