Good morning all

I have 3 Kindle Fires; a Fire HD 8.9, a Fire HD and a Fire HD 7. Something is strange - when I am on a pc or on the Kindles and I attempt to deliver an app to one that doesn't already have it; I only see the HD 7 listed. When I select "Where are my other compatible devices" it will show the other 2, yet, I cannot select either one of them.

This all came about because my son was trying update his Call of Mini Infiniti, we got the update screen on Amazon Apps but we could not deliver it to his specific Kindle.

Appreciate any help on this.