What I have notice so far is that in one collection you have id being a string and in the other it is a number. The string “5234” is not the same as the number 5234.
The you want the id 1233, the number as in
to become id “1233” the string as in
In the result document you show buCode:“LMFR” but I do not see any source field with this field name or value. Please provide real sample documents rather than made-up or redacted document.
You result documents are not valid JSON, so we have a hard time to know what you really want. Make sure the semicolons, the braces and brackets are all correct.