Sync Endnote on 2 computers & copy code/reference - working with Scrivener, Endnote and Word

I use Endnote Web to sync two computers to the same library. I also use a program called scrivener (not word) to write in. I copy the reference from endnote library in scrivener. By copy the reference I mean I copy the code corresponding to the reference, so that once the document is complied in word I can update citations and footnotes and the code will convert to the proper text.

My problem: the code keeps changing.

The code I copy into the document stops corresponding to the same reference as for some reason the library changes the code. I don’t know if this is a problem using endnote web? But I don’t understand why the number would change.

eg: {Hammerton, 2005 #1653@249} 1653 was copied from my endnote library on my 1st computer. But on another computer the number has changed to 1622. Needless to say the document does not correctly update anymore I just get a whole lot of code in my footnotes. 

Is there a way to fix this? (other than only updating portion of the document on the original computer it was written on… obviously that is a pain and not convenient). 

I realise I might have to go through and put in the codes again, but I don’t want to do this if it’s just going to change again anyway.