Validate PURL API says pkg:maven/org.kie/kie-dmn-model@7.44.0.Final does not exist in the upstream repo, but it does?

https://public.purldb.io/api/validate/?check_existence=true&purl=pkg%3Amaven%2Forg.kie%2Fkie-dmn-model%407.44.0.Final

```json
{
"valid": true,
"exists": false,
"message": "The provided PackageURL is valid, but does not exist in the upstream repo.",
"purl": "pkg:maven/org.kie/kie-dmn-model@7.44.0.Final"
}
```

https://mvnrepository.com/artifact/org.kie/kie-dmn-model/7.44.0.Final

I can't make sense of this, I would have expected the API to return ```"exists" : true```