Disable Adobe PDF Reader in IE 11

Is there a registry key that will disable the Adobe PDF Reader in IE 11.  The user has Acrobat Reader DC version 2019. They do not have the Add-on in IE 11, but pdfs still open in IE. We need to disable so the new Unified Shared Experience, Send As Attachment will open an outlook message to send.  Please let me know how to disable or another way to make the new feature work.  We have many upset users who are not happy with this change!

Thanks.