Dropbox Business: Disable "Request an invitation" popup for users after sharing

Using Dropbox Business Standard:

When a user shares a folder with external users via their email, they get this pop-up:

This is leading to numerous requests from users, not realizing that this is unnecessary in order to share their folder. Each requests results in a notification email, badge, and needing to deny the request.

We do not want to add externals to our team at all. In our admin console, we have disabled "Members can invite people". However, they can still make these requests.

Could you please provide a way to disable this popup? Thank-you!