When I enter a legit item number in BM-A, quite often I just get a blank screen, or the list only has one item.  The BOM's in question actually have many items, but are not show.  I have used my two year old persona to determine that if I just click on the  "A-Z" icon, and do the sort, all the items then are shown in the window.  This looks like a bug, and had me reverting to Classic to edit BOM's.

Thank you so much for your reply.  It didn't address the problem, but it did add to the number of posts you have.  If you don't know an answer, maybe you should just not reply.

Charlie -  
 
I think he was referring to your signature.  I know you are on a newer version but your signature indicates an older version (like 4 years ago) so given what he knows from your post, it is a valid point.  
   
That being said, if you are on the December update, are you up to date with patches using SM-V?