Turns out 3I/ATLAS is not behaving anomalously, it's vapour trail is not pointing towards the sun, it has not visited our solar system before, and there's no reason to think it's not a comet. In fact, all the evidence points to exactly that conclusion;
https://sites.psu.edu/astrowright/2025/07/18/avi-and-3i-atlas/
Disappointing for the UFO-philes out there, but there you have it.