In the "End Credit" scene of Avengers: Infinity War (2018), we saw Maria Hill and Nick Fury driving in the street and then there was a message on the radio. Nick then asked Maria, "what is it?" Maria answers, "Multiple bogeys over Wakanda, more powerful than New York". After that, they turn into dust by the snap. So that means when they were talking, at the same time Thanos was trying to snatch the Mind Stone, or already did, and was ready to snap.
Now the main point; all those "space-crafts" carrying Thanos' armies landed over Wakanda much earlier. Then what were those "multiple bogeys" Maria referred to? What was going on over there at that moment?