In which version of the program. I think there is a glitch in EndNote20 versions that shows one more than the number chosen. (see Problematic bug/error in EndNote 20.0.1 - Wrong number of authors in some styles) – The current workaround was to reduce the max number of authors by one from what it should be – and I would save it as an output style with the -fixes-glitch so you can return to the original, once the software is fixed? That thread also reports that it hasn’t been fixed in EndNote 21.1 - which is the most recent release.