I've had this trackpad for some time and it just started working only when USB connected to my Mac, even tho it is 100% charged. I'm running Mojave 10.14.3. It works perfectly when connected, not at all when not.
iMac 21.5", macOS 10.14
External magic Trackpad?
Set up your Apple wireless mouse, keyboard, and trackpad - Apple ...
Connect a Bluetooth device with your Mac - Apple Support
Using a Bluetooth mouse, keyboard, or trackpad with ... - Apple Support
Pair a third-party Bluetooth accessory with your ... - Apple Support
Resolve Wi-Fi and Bluetooth issues caused by ... - Apple Support
Apple USB-C Charge Cable Replacement Program - Apple Support
External magic Trackpad?
Set up your Apple wireless mouse, keyboard, and trackpad - Apple ...
Connect a Bluetooth device with your Mac - Apple Support
Using a Bluetooth mouse, keyboard, or trackpad with ... - Apple Support
Pair a third-party Bluetooth accessory with your ... - Apple Support
Resolve Wi-Fi and Bluetooth issues caused by ... - Apple Support
Apple USB-C Charge Cable Replacement Program - Apple Support
Yes, a Magic TP2, model A1535
Trackpad problem
