HabPanel Page unavailable from 1 tablet

Is there a minimum requirement or something for the HabPanel page to open?
I am trying to setup an old Android 4.4.2 tablet as a HabPanel but the page remains white for several minutes, then says the page is unavailable. I have tried the built in browser, Firefox, Chrome, and Opera, same behavior. My Fire 7 connects and displays HabPanel with no problem.

I am working on a tablet using Android 4.4.2 with no problem.