Wiki breacrumbs bug - path out of order, returns page not found

I have installed the paid Wiki plugin and am finding a display error in the way the breadcrumbs are presented.

All my settings are defaults as per the user manual: slug is /wiki

One one of the top level wiki pages, i.e.,
the breadcrumb is displayed as:
Wikis > Content

The hyperlink on the "Wikis" breadcrumb points to /wordpress/wiki/, which returns a "page not found" error.

On a 2nd level wiki page, i.e., the breadcrumb displays as:
Content > Wikis > Subcontent

Firstly, the breadcrumb is out of order - the "Wikis" link should be first, followed by the "Content" link. Secondly, the "Content" breadcrumb links correctly to the intended wiki page, but the "Wikis" breadcrumb links to the same /wordpress/wiki/ page that returns a "page not found" error.

I did not find this behavior with the Wiki Lite plugin; it seems unique to the way the paid Wiki plugin generates the breadcrumb.

Any assistance most appreciated.