BlockNote fails to load page when a list item contains non-list block content

Have XWiki Jetty/HSQLDB 18.5.0 with the experimental BlockNote editor installed. Configure BlockNote as the default editor.

Steps to reproduce:

1. Create a level 1 numbered list item.
2. Press Enter, and press Tab to start creating a level 2 numbered list item.
3. Do not create the level 2 item content.
4. Instead, create a normal paragraph.
5. Save the page.
6. Edit the page again with BlockNote.

Alternative to steps, use below wiki syntax as example.

1. (((  
   List one

(% style="color:default;background-color:default;text-align:left" %)  
some text  
)))

(% style="color:default;background-color:default;text-align:left" %)  
Lorem ipsum dolor sit amet, consectetur adipiscing elit

(% style="color:default;background-color:default;text-align:left" %)

The list item contains regular paragraph content some text inside the list item block. When BlockNote tries to reload the page, it fails with:

Failed to load document: Error: Only sub-lists are allowed inside list items in BlockNote

Only editing in wiki mode and correcting the line or disabling BlockNote and correcting the bad content solves the problem of further editing BlockNote.