it seems odd that the navigation bar displays the phrase "Advertiser list."
There is a LINK in the CAS Navigation Bar titled "Advertiser list". That link takes the viewing user to a listing page of all members that have viewable classified ads.
The "Your content" Navigation Section is a SPECIAL sub section of the "Advertiser list" for Classified ads.
The PARENT of "Your content" is "Advertiser list". Classifieds >> Advertiser List >> Member Page (which a Member page has several filter links that take the viewing user to a specific filtered listing of Ads and some sub content like Offers, Transactions etc).
What you keep highlighting in your screenshots is the
BREADCRUMB, which has nothing to do with the
NAVBAR. Navbar and Breadcrumb are two completely different things. When viewing a piece of content the BREADCRUMB is a special hierarchical link chain for a given piece of content or page. The reason "Advertisers list" is on the breadcrumb is that a CAS User Page (which the default is "Your open ad"), is the CHILD of the PARENT "Advertiser list".
There is no "Your content"
PAGE. That is just a Navigation Section. If you click on "Your content", you will see that it takes you to "Your open ads" as that is the default CAS User Page.
If you look at the "Advertisers list", the LINKS take the view user to that users CAS User page, which is "Your open ads".
What you keep calling a BUG is "As designed" and it follows the standard breadcrumb philosophy that XF, XFRM and XFMG set.
Marking this as "Is designed".