At certain heights you are in space and space is international. Anything above 110km is normally considered space, anything below 60km is a country's air space, anything between is a grey area.

That's why the gean BND had it's Space theory to justify it's spying.

The chinese was way below that a ca. 19km

I’d say it’s best to think of that gray zone as more of a nobody really operates here zone.