The DJI Mini 2 SE is compatible with the DJI RC-N1 Remote Controller.
The smartphone clamp of the remote controller houses the antennas. To improve the signal, make sure the antennas are pointed toward the aircraft.
Check the user manual for more information about setting the antenna direction.
Additionally, 2.4/5.8 GHz wireless devices can cause interference to the signal. Please avoid high-density Wi-Fi signal sources, and consider turning off the Bluetooth on your mobile devices, as well as idle Bluetooth devices.