problem of multiple references in one in-text-citation

I use EndNote X8 and Microsoft Word mac

I am currently using in bracket style for in citation text : [1,2,3] which later is linked in my bibliography as

  1. reference 1

  2. reference 2

  3. reference 3

In some cases, multiple references somehow accumulate in one in-text-citation and just appear in the bibliography all together as one. Ej.

in text citation: [1] 

in bibliography as:

  1. reference 1;reference 2;reference 3

Is there a way of fixing this problem of multiple references in one in-text-citation?

This is a setting in the output style you are using, grouping citations.  Edit> output style>your chosen style, and see the “numbering” settings in the citations section.  turn off the grouping option and save as a new style (do not use the same name!) - then go to your manuscript and change the endnote ribbon to the newly named output style.