Okay, everything is clear now, thx for the precision !
Will qtwayland5 be installed by default ?
I installed qtwayland5 and tried it again : it works but differently from when I use zsh
When I use zsh by default, the window is autosizing to the current resolution, which makes it ugly, but usable :
When I use bash by default, windows does not autosize anymore, which makes it nicer but unusable :
Is there somewhere a parameter to configure this autosize by default ?