Hi!
I’m also using Oxygen theme and facing the same problem with the sidebars in the full-width template..
I have a full-width page which used to be functioning as it’s supposed to do but, for some reason, now it’s displaying the Secondary Sidebar. For the Primary Sidebar, although none of the widgets there is shown, the area itself is kept white.
If you’d tell me what you’ve found out it will be great.. thanks in advance.
