When the trims and controls are centered, the servo arms should be about 90 degrees to the tail. Something like the picture. If not, it is possible one of the servo arms has shifted. If that is the case you will have to remove the control board to fix it.

If that is not it, then the sero may be damaged. You will have to buy a new fuselage. about $42.

Photos are from an original Aerobird, not the challenger, but you should be able to get the idea just the same.