Application Insights: Missing all telemetry — Ingestion issue since linking workspace

Problem description

I am experiencing an issue with Application Insights where, after creating and linking a managed workspace to the Application Insights resource, all telemetry data is missing. Standard metrics show a high volume of requests, but log-based metrics remain at zero, and no data appears in the requests, dependencies, traces, or exceptions tables. I sent a test event from my app, which received an HTTP 200 response with items received and accepted, but the data does not show up in the workspace after more than 15 minutes.

Environment

Application Insights resource configured in workspace-based mode. Managed workspace linked to the resource. Public ingestion enabled. Daily cap disabled. Link provisioning shows Succeeded. An app hosted on App Service was used to send a test to the connection string endpoint.

What I've already tried

I confirmed the issue started on September 23, 2026, right after creating and linking the managed workspace. I checked configuration elements such as successful provisioning, enabled public ingestion, and disabled daily cap. I sent a test event from App Service to the ingestion endpoint; it returned HTTP 200 with items received and accepted. Despite this, the event did not appear in logs after more than 15 minutes. I have not tried any further diagnostics or checks beyond this initial collection.

Current status

The latest status confirms that standard metrics continue to show traffic, log-based telemetry remains empty, and the test sent was accepted but no data appears in the workspace. It remains unclear where in the ingestion pipeline the data stops. I am seeking guidance on how to trace the accepted item through the backend pipeline and identify why no data reaches the workspace. I would also appreciate confirmation on whether any ingestion-time transformation is configured on the workspace.