Flightradar24 on iOS knew my location without having access to it

Here’s what happened: I was driving nearby an airport with my iPhone connected to CarPlay. I received a push notification from Flightradar24 welcoming me to that airport. But Flightradar24 wasn’t opened, wasn’t in the background, wasn’t active, doesn’t have background app privileges (I’ve unset it manually months ago) and had location privileges set to “only while using”. Flightradar24 doesn’t have Bluetooth access but has Camera access. But again, it wasn’t opened nor in recently active apps. WTH?