it appears its hot because they inverted how cold works. normally in superconductivity, the cold works it cools the one material, then the second material works for superconductivity, because of the temperature in the first material.
but in lk 99, they cool the second material and let the first material stay hot. this way the second material being cooled the superconductor works at room temperature.
Then the scientists trying to replicate the superconductivity try cooling the material, and they cool the first material and this destroys how the first and second material function, when they should only cool the second material and leave the first material not cooled.
in shape it works like the description below,
the hemisphere is a half of a solid sphere. with the flat side facing upwards. the bottom side is held in a 2d holder so the hemisphere can tilt.
the hemisphere has a main material straight through the hemisphere center, the second material i will call main rod. the main rod sits in the hemisphere with a tip protruding through the curved side of the hemisphere to touch and function with the object the main rod moves like a pencil drawing on paper.
the hemisphere is moved/tilt, by 4 rods placed in a square shape on the hemisphere. these 4 rods are the first material.
as you see the rods move the second material inside the hemisphere and this is using cold to provide less resistance or make moving the hemisphere easy, this is normally how superconducting works. but lk 99 cools only the main rod inside the hemisphere.