Can't add multiple collapsible sections without adding lines in between

[malvidah]

replicate:

• insert collapsible section
• press enter until i get to a new line
• try to add another collapsible section and it dissapears and moves me back into the previous one
• create 2 lines and i can add another

rather minor issue but noting because this is not clear to people editing and would require some experimentation + it looks awkward