Issues adding an auto-focus sensor

[Jerry Camel]

I have a CloudRay C-Series laser head and a CloudRay autofocus sensor. The issue I'm having is that the sensor is getting in the way of the material. It's a 20mm/50.8mm lens. My focus point is only about 3.5 mm below the nozzle. Most folks say they are about 7 to 8mm below the nozzle. Is there a way to adjust the position of the lens a little lower in the tube, perhaps? When the machine auto-focuses, the bed doesn't lower enough to get the sensor trigger off the material.

Thanks.