Never seen anyone have this specific problem but if you have OEM bixenon headlights there is a sensor on the driver's side rear lower control arm that is notorious for causing issues. It measures suspension travel and aims the headlights up and down to compensate. This sensor could be broken and flopping around or otherwise malfunctioning. Here's some info: https://www.golfmk6.com/forums/showthread.php?t=68711
If that sensor turns out to be your issue they can be had cheap from china (no idea on quality but worth a shot since OEM costs ~$160):