HID and xenon are the same thing. The aftermarket kits that replace the bulbs in halogen headlights tend to be a bit slow to get to full brightness. When you first turn them on, they flash brightly, then dim down to about half power before brightening up to full power over a second or so. This is not usually an issue as once they are on, they are on, and main beam uses the same bulb, just the beam pattern altered by the shutter behind the lens. However, if the headlights are off and you flash main beam, you may not get full brightness straight away, which kind of defeats the whole object.
After yours have been off for half an hour or so and the ballasts have cooled down, could you switch them on and see what happens please? Also, what are you using as DRLs now?