What exactly is the detector? If it’s an electronic, then when it’s on it surely produces it’s own set of waves. Waves that could affect the particles shooting through the slits. There are too many variables here to just determine that the atoms “know they are being observed.” To me this just seems egocentric. And like a comment said down below, bouncing atoms can cause a greater affect on a micro scale that’s being overlooked. There is definitely something weird going on, but we fail to realize that we could be jumping to conclusions. Sabine Hossenfelder even debunks this quantum eraser theory in one of her videos that’s worth a watch.