This may be the problem, but I could just be misunderstanding you also.
Below is a pic of a Excal Lumizone, exact same as Varizone, only it lights up. To sight in at 20 yards you need to use the main cross hairs. The flat lines that intersect, are you using this for your twenty? The big bold lines are the ones that adjust with elevation and windage and the ones you set for 20 yards. The others, the trianglesget adjusted per the speed of your CB with the speed ring on the end of scope for you 10, 30 40 and 50, 10 being the one above main cross hairs. Are you using the top triangle for your twenty, it is for the ten. If so it will not adjust with the screw.