My article previously used Sidebar Panel Top (which is always on by default) and Sidebar Panel Bottom. I wanted to remove SPB so I erased the text but it still shows up as a beige box on the right but with no text in it and it places a hard line break for the main content (so I'm only able to use 3/4 of the width of the page). I tried clicking on the X ("Remove Prompt") button for SPB but it did not work. The article did not save after being removed. When I clicked on the "Add Prompts" button on the quick menu at the bottom of the page and used the slider to close SPB and clicked the "Done" button, SPD would disappear but then re-appear a few seconds later. I tested this with Sidebar Top and now it's stuck on my page and can't be removed either.
1. Open a sidebar prompt. 2. Attempt to close it via X ("Remove Prompt") button or the sliders in the Prompts sub-menu 3. Sidebars will either disappear and re-appear soon after or will not disappear at all.
This affects anything in the "Add Prompts" button, including Generic Prompts and any of the Section-specific prompts. Thankfully if you have no text in other prompts they won't appear in your page and Sidebar Panel Bottom is the only one which persists even with no text in it (but the prompts still appear in the article editor which is annoying but not important).