The plugin was designed to make a single row of tabs only on desktop browsers. On narrower browsers (such as on mobile devices) the display of the tabs is intended to change to an accordion to prevent the tabs from breaking to a second row.
If the number of tabs used is such that it breaks to two rows, you can edit the responsive breakpoint in the media query so it changes to the accordion view at a larger browser width by creating a customised version of the stylesheet or by changing the value of the ‘Responsive -> breakpoint’ parameter in the Tabby Responsive Tabs customiser add-on.
If the total width of the tabs is only a little too wide to fit in a single row, it is often possible to make some changes to the styles (either with a custom set of styles or via the customiser add-on) to make the tabs sit in a single row by reducing the font size and the left & right padding of the tab titles and the space between the tabs.
