How to renew a custom hostname's custom certificate in Cloudflare

Question

I am sorry if the title is confusing, but I have a problem. I am going to keep this as simple as possible. I have several custom hostnames in my zone in Cloudflare. Some of them are using SSL certificates provided by Cloudflare, but the others are using custom-uploaded certificates. I have a C# application that updates the custom hostname certificate if its expiration date is approaching (the certificate is provided by the client). But consequently, I notice that the application is returning a Success 202 result, but the certificate is not renewed. When I try to update the certificate from the Cloudflare UI, everything is OK. This is the request that I have been using:

PATCH URL:https://api.cloudflare.com/client/v4/zones/{zoneid}/custom_hostnames/{identifier}

Body: 
{
    "method": null,
    "type": null,
    "status": null,
    "settings": null,
    "certificates": null,
    "wildcard": false,
    "custom_key": "-----BEGIN PRIVATE KEY-----MIIEowIBAAKCAQEAwQHoetcl9+5ikGzV6cMzWtWPJHqXT3wpbEkRU9Yz7lgvddmG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\nlv6XTQaMyf6n1yjzL+fzDrH3qXMxHMO/b13EePXpDMpY7HQpoLDi-----END PRIVATE KEY-----",
    "custom_certificate": "-----BEGIN CERTIFICATE-----MIIDtTCCAp2gAwIBAgIJAMHAwfXZ5/PWMA0GCSqGSIb3DQEBCwUAMEUxCzAJBgNV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\nYbjM2rxXiyLGxB4Bol7QTv4zHif7Zt89FReT/NBy4rzaskDJY5L6xmY=-----END CERTIFICATE-----",
    "txt_name": null,
    "txt_value": null,
    "certificate_authority": null
}

Authorization: Bearer Token - ApiToken

Note: The private key and the certificate are demo examples.

And the response is:

{
    "result": {
        "id": "b9f1a37d-7dcc-4d0d-bd4f-8c53b574d9f0",
        "hostname": "testhostname.demo.com",
        "ssl": {
            "id": "6aecbd4a-4a27-4818-8d6e-b98ff2abb11d",
            "status": "active",
            "hosts": [
                "testhostname.demo.com"
            ],
            "issuer": "LetsEncrypt",
            "serial_number": "847576949374596927022746968013864566661043",
            "signature": "SHA256WithRSA",
            "uploaded_on": "2023-09-15T13:56:01.305065Z",
            "expires_on": "2023-12-14T12:26:32Z",
            "settings": {
                "min_tls_version": "1.2"
            },
            "bundle_method": "ubiquitous",
            "certificates": [
                {
                    "issuer": "LetsEncrypt",
                    "serial_number": "847576949374596927022746968013864566661043",
                    "signature": "SHA256WithRSA",
                    "expires_on": "2023-12-13T12:26:32Z",
                    "issued_on": "2023-09-14T12:26:33Z",
                    "fingerprint_sha256": "c2aa8261c5565g535fgf7s8d6g8s8h8h4hihfidf6g8sdhg8s8d8gh3h4h5k34jh5",
                    "id": "b38d6a9b-caeb-418d-9904-1fd8dd24e0f2"
                }
            ],
            "wildcard": false
        },
        "status": "active",
        "custom_metadata": {
            "customerKey": "$(CustomerKey)",
            "environment": "Staging",
            "projectId": "c6a97aa9-1150-4010-adec-58c95ef96407"
        },
        "custom_origin_server": "testhostname.demo.com",
        "created_at": "2023-09-13T13:56:01.32642Z"
    },
    "success": true,
    "errors": [],
    "messages": []
}

Note: The example includes demo values.

The result is successful, but for some reason the certificate is not updated. Any ideas?