Dual aileron function:
First aileron goes to the normal port, second goes to ch 6 (Aux / Aux1 depending on how the RX is labeled)
If using the radio's reverse functions for BOTH channels and the closest you can get to the way you want things to work is correct ailerons and reversed flap function then swap which aileron servo is plugged to which channel.
Remember that reversing one channel might or might not affect both. This changes with brand and model of the radio and whether it applies the reverse switch or the mix first. There seems to be no consistency about this even within any given brand.
So... try the AUX (channel 6, Aux1... whatever they labeled it) reverse function as well as the Aileron channel's reverse function.
The same applies when doing Elevon, except you'd use the elevator channel instead of Channel 6
Its really common for me to see people asking how to fix correct aileron and reversed elevator being the closest they can get to correct operation.
The fix again is to swap what servo is in what channel.