A Bluetooth connection should be more stable in general. The gear display can be missing for Atom bike like it is for all Wahoo trainer and bikes. There is nothing you can do. It must be implemented by Zwift.
As mentioned by our dear Zwifter, you can use BLE, however, we suggest checking for wireless signal interferences, such as microwave ovens, wireless speakers, power sources, etc, so you can have strong reception.
If you have any other questions or concerns, let us know here or contact us directly, we’re always around and happy to help!