EndNote 21 missing numbering progression in PowerPoint

Hello,
I am really a newbie in EndNote and I was trying to add a citation/reference in MS PowerPoint, but if I try to use one of the styles with numbers (IEEE, Vancouver, Nature, Science, etc) there is not numbering progression, all of them are set to 1.
If I add all the reference at once there is progression, but if I add another it starts from 1 again, and in any case the citation is always 1.
Is there a way to fix it?
Thanks