@jonas.smedegaard : Thank you for adding this item to the tracker after my review and for the ping by email.

That's a good behavior. Thanks again.

Perfect. Thank you @mak !

@zlatan.todoric : This one is not fixed, even with a fresh OEM PureOS ( I just tested).

@zlatan.todoric : It was fixed upstream on end October. Sorry for not reporting it back here and thanks for the reminder. This thread can be closed.

An idea for a quick workaround:

gsettings set org.gnome.desktop.lockdown disable-lock-screen true

maybe something like this (not tested, but you get "the spirit") can be executed at same time as launching the distro-installer.

it is only matter of updated package in this case.

Thank you for the answer.

Ok, I'll retest in a month, it will probably work because meanwhile, for professional needs (I'll teach Krita course in Paris in a week), I installed a Fedora 26 and didn't ran into this issues on same hardware.

Thank you. Nice to meet you too!