Thanks, I agree with the VCDS and sensor issue.

It shouldn't happen when parked on a slope, unless you are at a
really steep angle, which I am not. If it did, these things would be going off in thousands of VAG cars every day.
The fluid should cover the sensor and I think there is enough between Max and Min that angle should not matter unless it is low. on the level mine is spot on Max, so this shouldn't go off.