Some people’s calluses disappeared after a few months in space
Living in the ISS in zero-g is very different than living down on Earth, where the force of gravity is much stronger. If you live in an environment where you spend most of the time floating and moving around via footholds and handles, your feet will probably go through some changes.
Several astronauts reported their callouses went away entirely after a few months in zero gravity. That is because their soles were not getting as much wear and tear as they would have on Earth. The tops of their feet, on the other hand, grew rougher since they would use them to hook onto footholds.