Response from LEGO SHOP
30 July 2020
Emily, Customer ServiceWe're sorry to hear that you had some trouble connecting your hubs. If it's happened 3 times now, it's not likely to be a technical problem with the hubs themselves. To get your hubs working, first, you'll want to make sure that the devices you're trying both meet all the specs listed at LEGO.build/DeviceCheck-BV. If your devices meet the requirements but aren't on the tested device list, they'll likely work, but it might not be the smoothest experience. From there, uninstall and reinstall the app. This ensures that you have the latest version. During this process, you'll want to make sure that you accept all requested permissions and that your Bluetooth is turned on. If you're using an Android device, you'll need to have location services on as well. (The app doesn't track or save location data, it just needs access for Bluetooth Low Energy to connect.) Next, make sure your hubs have a full compliment of fresh batteries. As shown in the set instructions, each hub takes a total of 6 AAA batteries (3 on each side). If you're using the Technic Control+ app to control a specific set, you'll then need to make sure that all your motors are connected into the right ports in the hub. It won't connect if they're in the wrong spot. (If you're using the Powered Up app to control a custom build, you don't have to worry about this!) Once all that's done, you should have no problem connecting. Just open up the app, wait for the prompt, and press the green on the hub briefly to get the connection going.