External Connections Items endpoint failed randomly since 10/09/2026

[xinzhaozhang1985]

Describe the bug

I know this might not to do with Graph SDK but a server side issue, but I don't have a easy path the report this. Since we are using Graph SDK to query external connection Api, people might have seen this issue as well.

This is Graph SDK returns via : graphClient
.External
.Connections[SearchConnectorName]
.Items[itemId.ToString()]
.GetAsync(default, cancellationToken);
ODataError:

<style type='text/css'> body { font-family: Arial; margin-left: 40px; }

    img {
        border: 0 none;
    }

    #content {
        margin-left: auto;
        margin-right: auto
    }

    #message h1 {
        font-size: 24px;
        font-weight: normal;
        color: #000000;
        margin: 34px 0px 0px 0px
    }

    #message h2 {
        font-size: 20px;
        font-weight: normal;
        color: #000000;
        margin: 34px 0px 0px 0px
    }

    #message p {
        font-size: 16px;
        color: #000000;
        margin: 8px 0px 0px 0px
    }

    #message hr {
        margin: 15px 0px
    }

    #errorref {
        font-size: 11px;
        color: #737373;
        margin-top: 41px
    }
</style>
<title>Service unavailable</title>

502

The service behind this page isn't responding to Azure Front Door.

---

Bad Gateway

Azure Front Door wasn't able to connect to the origin.
If the problem persists, use the troubleshooting steps to resolve the issue.

Azure Documentation

Error Info:OriginConnectionAborted
x-azure-ref ID:20260910T214930Z-186c45cf57658vcjhC1MNZst1s000000069g00000000sdsx

And this is what postman returns with the same Api:
https://graph.microsoft.com/v1.0/external/connections/[SearchConnectorName]/items/[ItemId]:
{
"error": {
"code": "UnknownError",
"message": "\n\n\n\n \n <style type='text/css'>\n body {\n font-family: Arial;\n margin-left: 40px;\n }\n\n img {\n border: 0 none;\n }\n\n #content {\n margin-left: auto;\n margin-right: auto\n }\n\n #message h1 {\n font-size: 24px;\n font-weight: normal;\n color: #000000;\n margin: 34px 0px 0px 0px\n }\n\n #message h2 {\n font-size: 20px;\n font-weight: normal;\n color: #000000;\n margin: 34px 0px 0px 0px\n }\n\n #message p {\n font-size: 16px;\n color: #000000;\n margin: 8px 0px 0px 0px\n }\n\n #message hr {\n margin: 15px 0px\n }\n\n #errorref {\n font-size: 11px;\n color: #737373;\n margin-top: 41px\n }\n </style>\n <title>Service unavailable</title>\n\n\n\n

\n

\n

502

\n

The service behind this page isn't responding to Azure Front Door.\n

\n

---

\n

Bad Gateway

\n

Azure Front Door wasn't able to connect to the origin.
If the problem persists, use the troubleshooting steps to resolve the issue.

\n
\n<a href="https://learn.microsoft.com/en-us/azure/frontdoor/troubleshoot-issues\" target="blank">Azure Documentation\n
\n

\n

\n Error Info:OriginConnectionAborted
\nx-azure-ref ID:20260911T134333Z-15bf5f54f66ksqf4hC1LONx86w00000008gg0000000055qt \n

\n

\n\n\n",
"innerError": {
"date": "2026-09-11T13:43:34",
"request-id": "a910ae69-61c1-4eac-9db1-5c0f92fbc8cc",
"client-request-id": "a910ae69-61c1-4eac-9db1-5c0f92fbc8cc"
}
}
}

Expected behavior

The External Item Api should be reliably return response rather than random throw front door error

How to reproduce

1. Query external Item api via Graph SDK
2. The Api is very slow (takes about 10 seconds to return if succeeded)
3. The Api failed randomly with the exception above

SDK Version

No response

Latest version known to work for scenario above?

6.5

Known Workarounds

The Api is throwing frontdoor error randomly

Debug output

Click to expand log

```

</details>


### Configuration

_No response_

### Other information

_No response_

[xinzhaozhang1985]

It has been confirmed that it is External Connection service issue by Microsoft Support team. This ticket can be closed now.
Issue Summary
Organization is experiencing HTTP 502 Bad Gateway errors when accessing the Microsoft Graph Connectors external item endpoint. Microsoft Graph returns UnknownError containing an Azure Front Door HTML response with 502 Bad Gateway and OriginConnectionAborted.
The issue began on 10/09/2026.

Expected Outcome
Our objective is to identify the root cause of the failures and performance degradation, determine whether they are related to an active service-side incident and provide guidance or resolution as soon as the Engineering investigation progresses.

Our investigation confirms HTTP 502 (Bad Gateway) failures and increased response times affecting requests routed through the backend service responsible for External Connections.

To accelerate resolution, the case has now been escalated to the Engineering team (Graph Connectors services) for further investigation.