In this commit, we simply set 'position' to 'sticky' on 'o_header_affixed' to avoid to manage it's position with 'padding-top' and 'right'. - 'padding-top' css property was used to compensate the navbar height at the moment where the stacking context change because of the fixed position. - 'right' css property was used to prevent the menu to overlapp the scroll bar. Part-of: odoo/odoo#99338