Does the preview app have full function?

I have created a project that is sending a notification when flagged and this works fine. When I create an “App Preview” the notification is triggered (confirmed) but no notification is received.
So I am asking if this is expected or do I have problem?

This is also the first time I am testing with blynk provisioning, although it seems that that part is functional.
I am using an android device.

Also, is there anything I can do about the very small text used in the “Time Input” widget yet?