Yeah, that's bothered me a couple of times in the past as well, but most of the time the search would start functioning correctly a couple of weeks after the corresponding schedule was actually released / made available for booking. Since I'd guess that NCE flights were made available around the same time as the other seasonal routes (which was back in September if I'm not mistaken, so 2 months ago!), I do find it quite bizzare that this still persists.
Of course it's nice that you can actually navigate all the way back or forward to your desired dates, but I've come across the exact opposite issue, that the "error message" would give me a piece of information like "flights from ATH to CGN are only available from 01/10/2021 until 31/10/2021 and from 25/03/2022 until 10/05/2022" and then
neither would be actually correct!
