nytimes.com/2019/05/26/us/…
1) Its our own classified tech
2) its the tech of another state
3) The sightings are caused by hysteria, false perceptions, etc
4) The objects are real, non-sentient, undiscovered phenomenon
5) The objects are evidence of ET Intelligence
The tech described seems unchanged over decades and if it were our best cutting edge tech, it would be evolving quickly.
The tech described seems unchanged over decades which wouldn't be true if it were a rival's.
That leaves us with explanations #4 & #5 both of which are problematic but if we try to put biases aside ET IQ seems shockingly reasonable