Unfortunately, as part of our commitment to your privacy, the extension works in a fairly one-sided manner.
This means the app is never pushing new data to your extension, instead the extension must request the list from the web-app.
In some cases this can lead to a miss-match between what you have saved in the app vs what you have available in the extension.
To fix this, simply open the extension settings page. This should sync your folders with the web-app.
If you need more info on finding the extension settings, we have tutorials available that can help.