Separating thesis chapters and now in-text citations have moved or dissappeared

Hi all, 

I am trying to finalize first 3 chapters of my thesis and am having major Endnote issues. 

I’ve inserted all my references into the first three chapters where they belong initially. Next, I’ve modified the output style to create a separate reference list for each chapter. 

Whenever I change the output style to the modified one (to separate the chapter reference lists), my intext citations are changed completely and some of them dissappear. If I change the output style back to the original then the issue is resolved. 

At the end of the day though I need the reference lists separated by chapter! ARGH! What is wrong with my new output style that is making it do this craziness??

I have Endnote X8 with Microsoft Word 2016 (Version 15.32) on a Mac. 

Attach your output styles (one that works and one that doesn’t).  (added in edit: to a reply message here, in case that wasn’t clear, so we can compare them for you).  

Could you compare the citation templates from your original and modified output styles files – they should be the same. [Go to the Endnote toolbar, select Edit > Output Styles > Edit (name of the output style file). In the output style dialog box, under the Citations section click “Templates”.]

Also, suggest before switching from one output style to the next, first convert the in-text text citations to temporary citations. then change the output style and click the “Update Citations and Bibliography” option in the Endnote tab on the MS Word toolbar.