Hello @annasha, I trust you are doing well today!
This might occur because there is a conflict with another plugin or with the active theme on your site.
Please run a quick check for a conflict with another plugin or theme to make sure that this is what causing this behavior.
Deactivate all other plugins and test if the Sidebar is working. If everything is well, activate one plugin at a time to find the one that causes this. Switch to a default WordPress theme to check if there is no conflict with a theme.
Follow the flowchart from our Getting Support manual:
https://premium.wpmudev.org/manuals/using-wpmu-dev/getting-support/
If there is no conflict with another plugin, would you please describe here the Sidebar Settings that you have selected and share a link to your page?
Let us know how it went!
Cheers,
Nastia
Thank you for using Custom Sidebars. I am marking this topic resolved because of inactivity. If you have any further questions we can reopen the thread or you can start a new support ticket. Thanks again!