endnote x8: bld 10063: windows 10: cannot group consecutive numbered citations

Hi there,

I am interested to group/collapse consecutive references numbers. But I cannot get it done. I am on windows 10, word 13.

I have checked under templates, numbering as ranges. I have also selected - (dash) instead of a semi colon as a separator. 

I see 12 13 14 instead of 12-14.

Can someone help? Attached is the endnote style.