Many materials are (weakly) diamagnetic. Take Silicon, for example. Even some metals are, including the noble metals.

I will add water, bismuth, and graphite (especially HOPG) as other classical examples of diamagnetic materials. Also, it is worth mentioning that the magnetic susceptibility of diamagnetic materials is temperature independent (unlike the susceptibility of ferro and paramagnetic materials).

The susceptibility of a superconductor below its first critical field value is equal to -1 (so susceptibility-wise the superconductor is a perfect diamagnetic material).

Parameters of high temperature superconductors being stable till temperature 93,50C are calculated in article “Macroquantum effects in condensed matter” https://arxiv.org/ftp/physics/papers/0111/0111182.pdf https://www.researchgate.net/publication/2167056_Macroquantum_effects_in_condensed_matter

Hot Superconducting structures working at normal temperatures are described in A. M. Ilyanok. Quantum-size electronic devices and operating conditions thereof (102 claims), US Patent No 6,570,224 B1 (1998)  http://ictt.by/eng/Default.aspx?tabid=82

https://www.researchgate.net/publication/278018597_Nanoclusters_as_superatoms_and_supermolecules

A giant diamagnetic effect and Meissner effect at normal temperatures can only be based on advanced nanotechnology that enables to create magnetic fields up to 10 Tesla at normal temperatures. In such fields, the vehicle can be made to levitate at a height of 20-30 cm.  At the same time it is unnecessary to create a complex configuration of the roadway, i.e., the road can be flat. The creation of such powerful magnetic fields is possible on the base of  discovery of the hot superconductivity (US Patent No 6,570,224). The nanotubes with a diameter of 14.5 nm and a length of a few microns, including carbon ones, there is a giant diamagnetic effect, which is like the Meissner effect in superconductors. This effect is observed from helium temperatures (-270°C) to temperatures of +93.5 °C. This effect was called "hot" superconductivity. For example, the discovery of the "hot" superconductivity clearly explains the effect of diamagnetic levitation samarium cobalt magnets in the man's hand and a live frog at room temperature. This effect is determined by the diamagnetic properties of the tubulin microtubes that make up the cytoskeleton of cells, rather than the diamagnetic properties of the water of the human body. The inner diameter of the microtubes is about 14.5 nm. As a result, the resonance conditions for motion of electrons inside the microtubules are created. This leads to a giant diamagnetic effect at normal temperatures.

Article Macroquantum effects in condensed matter

Conference Paper Nanoclusters as superatoms and supermolecules

Dear Alexander M. Ilyanok,

You would probably be interested in seeing the attached publication.

It shows water droplets levitating in air at room temperature above systems of permanent magnets. No superconducting or Bitter magnets were involved in the experiments.

Article Magnetic levitation of microdroplets in air

 repeat the experiment, might be not stable. the  question what is the type of this superconductor material.

More on the levitation of water.

At the Nijmegen High Field Magnet Laboratory, they did not limit themselves to the frog, they also levitated a droplet of water (and a bunch of other objects) using the same Bitter solenoid, as can be seen on their website.

http://www.ru.nl/hfml/research/levitation/diamagnetic/

Could be the effect of a residual field in your cryostat.