Troubleshooting pipeline used in Elastic Agent Agent policy

I have added the Custom Logs integration to a policy active for one Agent.

I have added a simple pipeline to this Agent policy using the " Ingest pipelines" setting under "Change defaults".

But after adding the Ingest pipeline, no more data is coming through from the integration.

How do I troubleshoot this issue? Are there types of logs I can check? I don't really know where to look at this point.