Why Is My IF/Switch Node Not Forwarding Data to the Next Node in n8n?

Based on the details you provided, it sounds like your workflow is experiencing behavior that can occur when using conditional nodes (like the IF or Switch node) in conjunction with a merge node or when operating in a legacy execution mode.

What Might Be Happening

• Merge Node Behavior in Legacy Mode:
  In older workflows that still use the legacy (pre‑v1.0) execution order, if you connect a Merge node to an IF (or Switch) node, it’s possible that both branches—for example, your "Message Sent" and "Message Recieved" paths—will trigger even if only one branch should actually pass data. In these cases, both branches “execute,” but you might end up seeing no data on either branch because one of the paths doesn’t really forward any data.
  This behavior was known in previous versions and has been refined in newer execution orders.

• Workflow Configuration:
  Since you’re running n8n@1.77.3 on Cloud, verify whether your workflow is using the latest execution order. If your workflow was built in legacy mode (or if you haven’t switched the execution order explicitly in your workflow settings), it might be subject to these legacy behaviors.

How to Troubleshoot

1. Check for a Merge Node:

   • Review your workflow to see if you have a Merge node connected to the outputs of your IF (or Switch) node.
   • If so, try temporarily removing the Merge node and test the IF/Switch behavior independently. By isolating the conditional node, you can verify whether data flows correctly on the true (or matching) branch.

2. Review Workflow Execution Order Settings:

   • Open your workflow settings and check if the execution order is set to the latest (v1) mode.
   • If your workflow is still using the legacy mode, consider switching to the updated execution order to avoid the issue where both outputs trigger.

3. Verify Condition Expressions:

   • Double-check that the expression or condition in your IF node (or the rules in your Switch node) references the correct data field and type.
   • Ensure that the logic precisely returns data for one branch and leaves the other empty, according to your intended filtering criteria.

Once you’ve confirmed your workflow isn’t inadvertently using legacy merge behavior and that the conditions are correctly defined, test again. This should prevent the unexpected triggering of both branches and ensure that only the intended data reaches the subsequent nodes.

If you continue to encounter issues after these checks, please share any additional details about how the nodes are connected (for example, if a Merge node is necessary or if there are other nodes in between) so we can further diagnose the problem.