It could be a trial run…or politically motivated…
There’s something that goes on everyday that might change the opinions of many on what is going on here. And that’s the smuggling of drugs and weapons on commercial airliners between West Africa and South American nations. There’s an entire air network that does this. The US and other authorities know about it, but stopping it requires enormous international cooperation.
Maybe someone took this plane for some purpose along those lines…
This UN document touches on the practice. Since most of these flights of drugs/weapons are over international waters in the Atlantic and between nations with weak central governments, there is little that is done about them…