To answer, it is important to know which reference types and where the data is in your records for those reference types. It appears that various templates for electronic resources (web page, electronic article, electronic book, blog, etc) have different fields it uses (combining "Year Cited " and “Date Cited” or "Date Accessed " or sometimes just “Year accessed” and they are used inconsistently in the various electronic types of templates as well. So to start, you need to look at where you want to keep the info in your record, what you want to include and, for which templates, and then adjust the bibliography templates in the Vancouver output style accordingly. I think the date accessed is more sensible than the date cited though. We know when it was cited, but if it no longer exists on that date, who cares. But perhaps the most recent Vancouver style manual might address this as well?
Since electronic sources evolved during the genesis of Endnote, most historical output styles need to be tweaked and user’s records probably need to be cleaned up to make sure they use the same criteria.
Once you have figured all that out, then you could ask for help again here.
With over 5000 existing styles, I don’t think they are reviewed or updated in any way by the developers, unless a specific request is made, and even then, I am not sure how it fits in their priorities. Thus, learning how to edit output styles and the underlying reference types, are good skills to acquire.
see these resources to learn how:
https://support.clarivate.com/Endnote/s/article/EndNote-Windows-and-Mac-Style-Editing-Guide?language=en_US