I will assume equal throws of right and left ailerons. It's pretty common to have a slightly different response right from left roll, if the model is driven by a single prop turning ccw when viewed from the front, has right thrust and downthrust. The fix is a small amount of differential (more up than down aileron) but learning when to push and pull elevator is a huge help.

Another issue that can happen is that the roll rate will differ right from left. The fix in this situation is a small increase in deflection on the slow side.

BTW- a contra rotating propeller(s) cures these issues. A contra does not cure motor torque tho, unless each prop is driven by its own motor which in turn rotates in opposite directions