When creating a copy plan for Confluence following the steps from the article Copy Confluence data in the Select Spaces section, there are only three options on the filter:

• All Spaces
• Personal Spaces
• Global Spaces

If choosing to show only Global Spaces, the spaces of type Knowledge Base will not appear in the list of spaces.

Currently, the only way to make the Knowledge Base spaces appear in the list is by selecting All Spaces, which, depending on how many spaces you have on the cloud site, might make it difficult to find the Knowledge Base spaces.

This is also not intuitive, as the Knowledge Base spaces aren't Personal Spaces, but a different type of Global Space

As a suggestion, Atlassian could include a new filter category for Knowledge Base spaces, or make them appear when selecting to show the Global Spaces