https://techcrunch.com/2023/08/09/boo-no-room-temp-superconductor/

Here's what I read from this website ;

The latest room-temp superconductor claims are losing their magnetism after several labs failed to replicate results.

Lead isn’t typically on the short-list of materials that researchers in the field turn to.

There’s a hitch, though: Today’s superconducting materials have to be chilled well below freezing before they do anything special.