This is due to discord limiting the widget to 100 members, its not good practice using the widget to get online members, a better solution would be to use a bot and create a small API to get the online members.

This is due to discord limiting the widget to 100 members, its not good practice using the widget to get online members, a better solution would be to use a bot and create a small API to get the online members. https://imgur.com/i4LfimE