Q:

On Page layout "required" is not working for lighting

I have ticked one field "Required" in Page layout, Its fine on classic but on lighting the same field is not mandatory.  Any Idea why? 
Lighting -https://www.screencast.com/t/5id0trFjg
Classic- https://www.screencast.com/t/VdPb2WW1

A:

This is a known issue and is being reviewed by the Salesforce team.  
Here is the link to the reported issue - https://success.salesforce.com/issues_view?id=a1p3A000000IYubQAG

