This depends on the layout of your theme.
The widget uses CSS to display multiple columns and not tables. Depending on how much room is available for the widget, it can happen, that there is not enough room for multiple columns including post counts and the colums will collapse to fit the available space.
So you either have to change your theme design to give the widget area more room or you have to create custom CSS rules for the widget to display the columns in another way – e.g. with display: table-column for each column to avoid wrapping. See the FAQ which styles you have to override.
But beware! Using fixed columns also means that the widget can be larger as the widget area in your theme layout and this can break the page design!
