https://www.wired.com/story/5g-network-stingray-surveillance-non-standalone/

"In North America and many other parts of the world, high-speed 5G mobile data networks dangled just out of reach for years. But as 5G coverage becomes ubiquitous, the rollout comes with an important caveat. Even if your phone says it's connected to the next-generation wireless standard, you may not actually be getting all of the features 5G promises—including defense against so-called stingray surveillance devices

To get 5G out to the masses quickly, most carriers around the world deployed it in something called “non-standalone mode” or “non-standalone architecture.” The approach essentially uses existing 4G network infrastructure as a jumping off point to put out 5G data speeds before the separate, "standalone" 5G core is built. It's like starting your cake-decorating business out of your cousin's ice cream shop while you renovate a new storefront three blocks away. "