Find My Phone app won't let me log on. user and pass are correct.

I can log on on the Website, but NOT on the device.

I'm sure to be logged OUT of the Website BEFORE I try the device.

I've quit the app and rebooted the phone.

Does anyone know what's wrong?

Thanks,

- Joe

iOS 9

iPhone 5s

Find My Phone App

Macbook Pro with latest Safari.