No Arrivals Available not disappearing at NGO

Not sure if this is a bug or if I am doing something wrong. But I sometimes get the “Nö Arrivals Available” notifications when all stands of my airports are completely full. This happens to me sometimes at INN, NGO or BRI when some of my planes waiting for the best time to depart to my connection partners. That’s good so far.
But then at INN and BRI I automatically will get new generic arrivals after my own planes have taken off and there are stands available again, but not at NGO. To get new arrivals at NGO I have to go back to the main menu and re-enter the airport, even though there are a few stands available.
It is definitely not a slot issue, because I have unlocked all generic planes at NGO and as soon as I left the airport and go back in there are arrivals available. Anyone else having this issue at NGO?

A new spot is available:

Plane has taken off:

A few minutes later (it doesn’t matter if there is only one stand or even more stands available)

After re-entering the Airport there are arrivals available:

Hi, i have the same problem at IAD.
What is Wrong?
Is there some manual for it!?
Thank you