KivyMD is a collection of Material Design compliant widgets for use with Kivy, a framework for cross-platform, touch-enabled graphical applications. https://youtube.com/c/KivyMD https://twitter.com/KivyMD https://habr.com/ru/users/kivymd https://stackoverflow.com/tags/kivymd
So it looks like it is not possible to apply column sorting to the first column of a table
The second column has the sort icon but the first one does not.