I think the 'cube in sphere' thing they reported was a sublaunched radar reflector:
Submarine-launched, radar reflector-toting balloons used to stimulate enemy air defenses can be traced back to a Cold War era Skunk Works program.
www.thedrive.com
Also, some of this may be optical illusions being tested against friendly forces using plasma and lasers:
The Navy has patented technology to create mid-air images to fool infrared and other sensors, offering a game-changing method of protecting aircraft from heat-seeking missiles. It may also provide a clue about the source of some recent UFO sightings by military aircraft.
www.forbes.com
As for the triangle things, those may be exotically powered drones like the TR-3B that has been increasingly rumored to be connected to Navy 'anti-grav' patents filled in the last few years:
TR-3B has the ASTRA code name. The first operational tactical recognition flight was in the early 1990s. The triangular aerospace nuclear platform was under the Top Secret and was developed in the AURORA Program money from the "Black Budget"
matrixdisclosure.com
So I expect a lot of UFO/UAP are 'black' projects testing their chops against 'conventional' forces.
There may be legit aliens involved, but I think a lot of it is just the same shit we saw with Area 51 and all the 'spaceship' sightings that turned out to be related to F-117 and B-2 development. Probably won't know till decades from now.