Hi ​@UittenbM 

Thank you for posting in the Lucid Community! I apologize for the delay in the response. I tested this on my end and found that the page range reflects the order in which the pages were added. For instance, I had my range set to page 1, and it showed my page 2 because I deleted the first page, and so this was the was the first created page. Additionally setting my range to 2, made page 3 appear.

Its possible that in the process of creating your document, you deleted a page or added a page impacting the order it is in confluence. If you set the range to 12 does that make the correct tab appear?
 

Hello Kelsey, thanks for your answer.
And no it doesn't solve the issue.
However I did discover what is causing this.
The first page in my Lucid document was set as a master page.
I tested this first by having the first page set as a master and next set the range for the 2nd page of the document. The result: 

The model displayed is the second page, which is the one set in the range field:

But as you can see the page tab displayed is the third one.

Next I converted the 1st page back to a normal page and tried again.
And then no more skipping of pages in case a range is set.
So still a bug?

Many thanks for your answer.