Mode Still Showing

Even after I’ve deleted this plugin after I was done with it. I am hearing about viewers still consistently seeing the Maintenance Mode screen still being visible. What can I do to get rid of this? I’ve deleted the Plugin and all their files, and I’ve confirmed in Incognito Mode that it can be seen 1 in every 3 visits or so. What’s going on and how do I fix it?

https://wordpress.org/plugins/wp-maintenance-mode/