Tabs on PCs and Macs

I’ve got a PC and do a fair amount of module development. Recently someone with a Mac mentioned to me that if you have a tabbed panel in a Chart Window, on a Mac the tabs don’t get stacked to fit the window width, they are on a scrollable bar. See image below.

Does anyone know if there is anything I can do in VASSAL to have the tabs stack on a Mac or something a Mac user can do to get them to stack?