Why are two identical fields not merging correctly in n8n?

Below is a checklist of things you can try to resolve the issue:

1. Double‑Check Field Names and Values
   Verify that the values in both inputs are truly identical. Even a small difference (such as trailing spaces, extra characters, or differences in capitalization) will cause the match to fail. You might want to log or preview the incoming data so you can see if any whitespace or formatting issues exist.

2. Use Fuzzy Compare
   In the Merge node’s Combine mode, there’s an option called “Fuzzy Compare.” When enabled, it tolerates type differences (for example, the number 3 and the string "3"). Even though you already attempted converting the value to a string, toggling Fuzzy Compare might help in cases where there are minor discrepancies or hidden differences.

3. Review Your Field Settings
   Make sure you have entered the field names correctly in the Merge node’s “Fields to Match” settings for both inputs. If you’re referencing nested properties, confirm that you’re using the proper dot-notation format (unless you’ve enabled the “Disable Dot Notation” option).

4. Check Input Order and Data Structure
   Remember that in Combine mode n8n only processes up to as many items as provided by Input 1. Double‑check that both data streams contain matching numbers of items and that the field being evaluated is at the same level in both items.

5. Review Merge Options for Clash Handling
   If the fields exist in both inputs, by default n8n prioritizes the value from Input 2 in the event of a clash. Although that setting is mostly for deciding which value to keep when merging, ensuring it’s correctly configured can sometimes shed light on other mismatches.

If after these checks the issue persists, you may want to try simplifying the example to isolate the problem. For example, create a minimal workflow with two Code nodes that emit data with the same simple field name and value. This can help determine if additional factors in your original workflow might be influencing the merge.

Feel free to let me know if you need further details on any of these points.