https://pagure.io/fedora-infrastructure/issue/12689

It seems that IPA doesn't process the tls cert signing operation requested through fasjson (stg) :

```

[+] 20250729-07:42 centos-cert -> Validating user [arrfab] with realm [STG.FEDORAPROJECT.ORG] against https://fasjson.stg.fedoraproject.org
[+] 20250729-07:42 centos-cert -> We can reach https://fasjson.stg.fedoraproject.org with realm [arrfab@STG.FEDORAPROJECT.ORG], so now asking for TLS cert ...
Generating CSR...
Uploading CSR for signature...
Error: could not sign the CSR (400: Failed to authenticate to CA REST API,

{'message': 'Failed to authenticate to CA REST API', 'code': 4016, 'source': 'RPC'}

).
[+] 20250729-07:42 centos-cert -> [ISSUE] : Unable to retrieve TLS cert
```

Can someone investigate what's happening ?