Check the connection first. Settings → Connections shows each tool's status. An expired or revoked OAuth grant (a changed password can do it) shows there, and reconnecting takes a minute.
Remember: no backfill. The queue proposes from live context, not history. A workflow that last fired the week before you connected will not generate an action until it fires again. To test a workflow, create a current example: send the email, raise the quote, place the order.
Check the scope. If a workflow needs two tools (invoices from threads need the inbox AND QuickBooks), both must be connected. The single-tool pages under integrations list what each connection enables on its own.
Volume expectations: a quiet inbox produces a quiet queue, honestly. The queue mirrors your real activity; it does not invent work. If activity is real and the queue stays empty for more than a day, contact us with the tool and the example you expected; in early access, a human looks at every one of these.