Shadilay anons, [they] are scared shitless.
Perfect time for the song :D
My reading of the available information is that the security issue related to:
Foreign operators, likely chinese, were apparently apprehended spying on the missile range.
They were regarded as armed and dangerous by LEO, so everyone was evac'ed.
The entire site and surrounding area was swept for bugs/explosives/other potential safety issues, perhaps even testing for fentanyl, know what we know about the movements of that through the country at this time.
The reason why there's no further info is because a security breach due to spy ops would be classified as a national security issue..