Your publiccode.yml template has wrong intendedAudience key/casing (not compliant with v0.5.0 of publiccode.yml)

BTW your example template linked on this page is wrong: https://guide.opencode.de/assets/code/publiccode.yml

As per https://github.com/publiccodeyml/publiccode.yml/discussions/277#discussioncomment-15649141

availableLanguages ISO country/language codes should be lowercase, but intendedAudience.countries MUST BE uppercase

Better provide the "best" spec-adherent example instead, I'd say.