can stainless steel be magnetic in some instances?
Yes, stainless steel can be magnetic in some instances. It is important to note that the magnetic properties of stainless steel vary depending on their composition, grade, work-hardening, and other factors. Some stainless steel varieties contain larger amounts of an allotrope called Austenite, weaking its magnetic properties. Nickel has the same effect on the steel. Typically, stainless steel with ferritic grades exhibit magnetic properties. Overall, the degree of magnetic attraction in stainless steel depends on their composition and microstructure.
Tell me more about the properties of Austenite.
Austenite is a form of steel but is not magnetic.

Also known as gamma-phase iron (γ-Fe), it is an allotrope of iron where the C atoms are randomly arranged throughout the available octahedral holes (of which there is one per Fe atom), there being insufficient C for a regular structure. In plain-carbon steel, it exists above the critical eutectoid temperature of 1000 K (727 °C), though other alloys of steel have different eutectoid temperatures, and it exists at room temperature in some stainless steels due to the presence of nickel. Austenite is essential to the manufacture of carburized steels. It is named after Sir William Chandler Roberts-Austen (1843–1902).