I have a 2019 Superb Sportline Plus. About 3 months ago the 'Front Assist Unavailable' warning displayed. It was intermittent and usually came on during a typical 10+ mile trip. The local Skoda dealer ran diagnostics but did not find anything! I, typically, only use the car about twice a week for short trips! About 2 weeks ago I found myself making a daily 30+ mile round trip for 6 days. After the first day the 'Front Assist' warning never came on and did not come on anytime during the 6 days. My car was then parked for 5 days and yesterday the warning, briefly, came on. With my, many years background in electronics I have 'guessed' that the issue is dampness/moisture in the radar unit. Modern electronics can react to even the slightest bit of moisture and if the electronics has even a 'pinprick' hole in the seal moisture will get in. Particularly if the electronics are on a vehicle kept outside! My vehicle is regularly covered in condensation in the morning! This might help anyone experiencing this issue and I am fairly certain it is out with the capabilities of the majority, if not all of Skoda dealers to find such a problem. I am, absolutely, not suggesting Skoda dealers are not competent but issues like this require 'very specialised' equipment to trace. If I am correct it is not repairable but would require a new unit to be fitted. I will be visiting my Skoda dealer shortly to discuss!