primary category doesnt work

Hi all, on the courses list page each course shown with the first signed course category in the list, categories are in alphabetical order. But what is the purpose of primary and make primary catgeory button if it doesnt shown anywhere? I mean for instance I make yoga for 1st category and wanna have the course shown with yoga category, but it is shown with ayurveda however this is secondaryand not so important. Thanks

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