Apparently, the layout was not "tested" after all. Otherwise, the issue with the extractor would have been noticed. Island solutions are only suitable for show kitchens (oh, oh, things are about to get heated here again! ;-), precisely because extraction can only be done in an extremely cumbersome way. So the layout is not only useless for cooking - if you want proper extraction, it also requires a lot of money. €2000 is not enough. Even for wall extractor hoods, €2000 is not top class yet. But from around €1000 you can be happy (with exhaust air).
So. Either:
1: cook little, then the ceiling panel works.
2: invest a lot of money, then the box lowers before cooking and goes back up afterwards.
3: rearrange the layout.
When I see what’s swimming in the grease tray of my hood after a proper Bolognese, I’m very glad I didn’t go for an island and/or downdraft. Otherwise, I would find all of that again on the fridge, cabinets, and windowsills.