It also may assist,to describe how you separated the RFC,how and where it was tested. It seems unfortunate that the same identical fault should appear on both halves.
If the fault is described accurately,it should take only one more splitting of the RFC,and the re-testing of the now disconnected six cable ends,to determine whether it is a fault,or a testing error.
Accurate terminology and result nomenclature,is vital. It is not "picky",to pull anyone up,on mistakes of this nature.
If you took your pregnant missus on holiday, to a foreign land,and asked regarding medical assistance,you would not be thrilled to find out it was 100 miles or 100 minutes or 100 pounds away...
With an accurate description of a circuit layout,together with test methods,and results,a fair guess can be attempted,at possible issues,and additional methods to apply.