Joining Zoom call as guest from Intune/Company Portal

Looking for guidance on configuring Zoom on Intune for joining Zoom calls as a guest. 

Some of our employees join vendor and client Zoom calls from Intune registered iPhones with App Management.  To improve the Zoom join experience we added Zoom for Intune to app management policies.  Some iOS users are unable to join as a guest.  When they click the meeting link, their 365 credentials are passed directly to Zoom without an option to join as guest.  Since we block passing credentials to 3rd party apps, they get a consent request instead.  

How can we configure our App Protection policies to enable our users to join 3rd party Zoom calls easily without enabling an Enterprise App in 365?