outlook mark email as read by it self

Hello,
I have a small problem but very annoying, since a few days outlook (web or app) is marking my email as read by it self.

I make sure the options for the preview pane is not responsable for that , so I configured outlook web and app to not mark email as read on preview or after x amount of seconds , but that does not solve the problem .

New Mail arrived and are mark unread , but if I do nothing and leaves it there , after a while, the new mail will be mark as read

Anybody came across this problem ?

Thanks