I just read the (pre-published) paper. It looks like exactly what they are claiming. It’s a small effect, but it’s definitely superconductivity, proven in multiple ways. It’s also maintained (very weakly) all the way up to 398K, which is insane.
Your not going to be building a room temperature MRI machine with it, but it’s there. Critically, now we have an example of a functional RTP superconductor, scientists can iterate around it to improve. That’s how most type-II superconductors were discovered/developed.