Columns are responsive, and are designed to wrap or "stack" based on the screen width or content width. This is set using the Stack Width option in the Columns dialog.

Please note that the editor display may be smaller than the final front-end content display, so columns may disaply as stacked in the editor but not in the final front-end content, so this should be considered when choosing the Stack Width option.

Please see - https://www.joomlacontenteditor.net/support/documentation/columns/creating-and-editing-columns#columns-stack