Unable to show toggles/tabs when right before/after regular bulleted lists

Our Zendesk theme allows us to create tabs and toggles using <ul> lists with a particular class. Each <li> is an individual toggle or tab.

In the new editor, if we try adding toggles or tabs after a regular bulleted list, the toggles/tabs don't work; each toggle/tab becomes a regular list item (the class is ignored).

We have found a workaround is to add <p>&nbsp;</p> (or to add text). However, we'd like to be able to not add a large space or additional text between for these to work.