UFOs are just spy drones with sensor jammers and detectors that are designed to look strange and unnerving to pilots so they will scope them out. Pilots are trained NOT to go by them or engage with them for fear of secrets leaking.
I think what changed is that the US decided to stop ignoring the "UFO"s. The Ukraine war has shown how important drones are and it's obvious that drones and balloons will play a huge role in any Taiwanese war.
Adversary drones are spying on the U.S. and the Pentagon is acting like they are UFOs. This gross inaction and the stigma surrounding unexplained aerial phenomena has led to a massive failure in U.S. military intelligence. It is likely that a wide array of explanations exist for the UFO mystery, and America's prevailing cultural issues and the general stigma surrounding UFOs was successfully targeted and leveraged by our adversaries. The U.S. Navy has a program of record for a Netted Emulation of Multi-Element Signature against Integrated Sensors, or NEMESIS, which is a quantum leap in electronic warfare. There have been reports of large drone swarms spotted over the U.S. and its outlying territories, especially near strategic installations. The U.S. Navy's top uniformed officer says the craft involved in the 2019 incidents off of Southern California remain unidentified. It is possible that the Pentagon's investigations into these matters is a lack of real expertise to properly evaluate the evidence. Step one is to admit that we have a major drone problem and fund a real intelligence fusion center to work these cases.