The support contact, marketing URL, and developer or company name listed in App Store Connect need to be real and functioning — a broken support link or a name that doesn't match your legal entity is a violation, not just an inconvenience.
Commonly caught when the support URL returns a 404, or points to a generic page with no real way to actually reach the developer.
"The support URL provided in your app's metadata is not functioning, per guideline 1.5. Please provide a valid link to a support page."