Unable to diagnose why Azure APIM fails to log to Event Hub - azure

Question

We've an Azure based solution that tracks user actions on a SharePoint web site. A SharePoint extension produces a JSON payload that is sent to an API Management resource with the task to log it to Event Hub.
Useless I describe next parts of the architecture since will go beyond the purpose of the question.
We're used to deploy the whole solution automating DevOps with a custom software.
In the last deploy the APIM seems unable to work properly. The request took about 3 minutes and ends with 502 - Web server received an invalid response while acting as a gateway or proxy server.
I get this error using postman where it should normally return a mocked 200 after logging to Event Hub.
This is the XML policy used:
<set-body>#{
var body = context.Request.Body.As<JObject>();
body.Add(new JProperty("event_id", Guid.NewGuid().ToString()));
body.Add(new JProperty("ip_address", context.Request.IpAddress));
body.Add(new JProperty("ingest_status", "unknown"));
return body.ToString();
}</set-body>
<log-to-eventhub logger-id="pagesLogger">#(
context.Request.Body.As<string>(preserveContent: true)
)</log-to-eventhub>
<mock-response status-code="200" content-type="application/json" />
This is the top-level ALL APIs policy:
<cors>
<allowed-origins>
<origin>*</origin>
</allowed-origins>
<allowed-methods>
<method>GET</method>
<method>POST</method>
<method>OPTIONS</method>
</allowed-methods>
<allowed-headers>
<header>*</header>
</allowed-headers>
</cors>
The weird thing is that also commenting log-to-eventhub I get an error response: 500 - The request timed out.
I tried to create another API in the same APIM resource but I'm still unable to get a 200 from a mocked response. Also creating a brand new APIM resource it's not able to solve the problem.
Enabling application insights on APIM did not help to get further informations. The same also with Event Hub diagnostics.
I don't expect a solution but I would really appreciate hints that help me diagnose the problem.

Answer 1

It was an Azure issue. Without changing anything after two days everything
is back to normality