The issue appears in browse views of Omeka S sites when a few conditions are met. This is more likely to appear in the real world when custom properties are selected in the site settings, but in principle could happen also with default values.

I'll illustrate this with a real case scenario.

There is an Omeka S side dedicated to publications. Under Site Admin -> settings, I select under "Browse body property" that the field "Publisher" is used:

This site mainly includes publications. Major publishers are themselves recorded as Omeka items. When I add a new publication, this has as publisher the relevant Omeka item:

This all seems fairly standard.

However, when I then visit the browse page on the site, rather than seeing the name of the publisher, I see a non-clickable URL as a string that corresponds to the url of the Omeka item of the publisher.

In this example, item 14744 is indeed the item with the title "Example publisher". But logically, the name of the publisher should appear here, not its url a string.

In the real world, this results in a confusing browsing page, where items that have publisher as a string appear correctly, while major publishers have that confusing url-string.

In principle, this could be even more confusing: if the primary "Browse heading property" selected in the site settings is an Omeka resource, then in the browsing page the clickable heading is an url-string: the active link is however not to the same url as the string text. Logically, this should be much less likely to emerge in the real word.

But "title" -> "publisher", or "title" -> "creator" combinations appear to be quite common cases where the secondary property chosen for browsing pages can reasonably be expected to be itself an Omeka S item.

I remain available to provide additional clarifications should the issue not be clear.