The options to manually select WiFi channels were removed after GO4 4.1.3 (see this reference).
Bottom line, the channel options are in 4.1.3 and below, but nothing higher, DJI took them out for some reason.
The options to manually select WiFi channels were removed after GO4 4.1.3 (see this reference).
Bottom line, the channel options are in 4.1.3 and below, but nothing higher, DJI took them out for some reason.