Admin/Registered Users Not Receiving Emails

I have a list of 90 people subscribed to my in-house “intranet” sorta speak. When I elevate a user’s privileges to anything other than a basic subscriber, they no longer receive new post email notifications. Their email address is not listed under subscribers or registered users and when I try to add them to either section, it kicks it back.

Any thoughts?

https://ww.wp.xz.cn/plugins/subscribe2/