Looks like they’re using standard chemical fuel which leaves a contrail. Any sufficiently advanced alien technology would have electrogravitic or fusion propulsion with no chemical contrail.
These are simply man made secret weapons. The best book that outlines the development of the aeronautical technology is “Intercept UFO” by Renato Vesco.
https://www.amazon.com/Intercept-UFO-Renato-Vesco/dp/B001MPQ3B2
Yeah I agree it’s not a “ufo” for sure.
Just thought the article was interesting since they chased and couldn’t catch it.