There is an bug in AR example project.
When I tested ‘HandheldARBlankMap’ example
following this ‘Augmented Reality Quick Start | Unreal Engine Documentation’
I had a problem.
reason of problem was ‘project name’
I think that the developer who made sample AR codes, made a some codes which including project name ‘ARProject’
Because of this reason, AR sample project name should be ‘ARProject’ for now.
If not, app will not work on mobile phone.