Many to Many mystery

Hello Community - 

I have a table that just refuses to create a one to many relationship and I cannot figure out why.  

The data is coming from our ERP system and I wonder if that is perhaps the root of the issue, but from the Power Bi side, I cannot see what is causing the issue.   I get the full green bars showing 1000 distinct, 1000 unique.  Actually, if I profile on the entire data set I get 11106 distinct, and 1388 unique, but still get the full green bars.    100% valid.   0% empty   0% errors. 

I have cleaned, trimmed, uppercased. 

I have removed blank rows.   

I have duplicated the table and isolated the column in question by removing all other columns - same issue.  

I have put all of the rows in table hoping to see where the duplications might be at the row level, but no rows are duplicated.  Yet if I do a count of the RMA number (the field that should be unique), I get multiple values...but those duplicates never show themselves on any rows.   I jut get a single row for each RMA number.    It's almost as if there is some sort of ghost field that is causing the duplicates that I can't see.  

Could this be something related to the source (ERP) or is there still something I've not tried in Power Bi?   Many thanks!