Sam,
Since you mention both variants, if the input and output variant differ in how the OBR is defined I’ll speculate that the path that can’t be found is relating to a specific field within the PATHCOPY.
I can’t say I’ve ever had IR tags problems with PATHCOPY, but when I’ve had the mismatched tags happen in a COPY operation the field does not get written to the output.
Maybe make a test message with every field in the OBR populated, (OBR|1|2|3|4|5…) and see which fields (if any) don’t cross over.
