Thanks for the quick reply and info!
Indeed, cpp highlighting works if set explicitly. However, while looking into this a bit further I found another… unexpected behavior.
I removed all languages from the highlighted languages list except for cpp and reverted the default language back to auto. The result was still a wrong highlighting. Opening the Inspector in Firefox revealed that the code is apparently recognized as vbnet - a language that was never in the list of highlighted languages (neither the default one nor any custom ones I tried for this issue)? Is this supposed to happen?
Kind regards,
Max