Mystile Sidebar blank

Hi
I installed the Mystile theme for my Woo Commerce site. I had problems removing the sidebar from pages, but eventually I got them away by choosing full-width template on Page edit. However, something has happened, I can’t see the sidebar now at all on the other pages like the blog. The sidebar is just blank. When I switch theme to another Woo Commerce theme, the sidebar is there. I have tried to reset all settings for Mystile, and even re-installed the theme. But the blank sidebar is still there.

Can someone help me figure out what has happened? I have not changed any codes.
Thanks!