Individual node testing fails when previous node has multiple outputs merged - is it a bug?

When a previous node has multiple outputs (Switch, Webhook with multiple methods etc.) sometimes I get this problematic behavior when testing the following node.

Here no item is passed forward, even though there’s an item:

But if I disconnect the other outputs, it works when testing:

This doesn’t happen when pressing the button “Test workflow” or when running in production. It’s only a issue when testing node by node.
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Information on your n8n setup

  • n8n version: 1.74.3
  • Database (default: SQLite): default
  • n8n EXECUTIONS_PROCESS setting (default: own, main): default
  • Running n8n via (Docker, npm, n8n cloud, desktop app): docker
  • Operating system: Ubuntu 24.04