I may be preaching to the converted here, but I found that after the 23.1 update, Knowledge Base failed to display article text and data. Menus worked fine, article text could be viewed on printer view, and prepared OK for email. The database was therefore unchanged. It was necessary to re-clone the phpbrain, phpgwapi and etemplate repos to retrieve the function, so undoubtedly there have been some updates there. We don’t use the wiki, so don’t know if that’s similarly affected.
Sorry again if this was obvious to everyone except me!!! lol