Greetings from Hauptmann in Hurst, Texas!
I use an iPad 4 Mini, so I can just offer a guess. First, check the side USB port on your controller, and make sure it isn't broken. There should be a horizontal tab visible inside the USB port, just above the the bottom. Inserting the cord upside down can easily break off the tab, as some pilots have discovered to their chagrin. Second, make sure the DJI Go4 App is properly downloaded and installed onto your new tablet. Third, make sure you have a good connection between the controller and your tablet. Turn stuff on in this order: 1. Controller; 2. Drone; 3 Tablet. Then activate the Go4 App. The App should recognize your drone.
If I've missed or forgotten anything in the above, someone please chime in with better info.
We have members in most counties of Texas. If you continue to have issues, I'm sure you can meet up with some of them to solve your problem. We also have over 100,000 members all over the world to help you advance as a pilot and photographer.
Glad to have you with us!