Had this issue just now. I had my fleet uniform set as my secondary costume slot and was wearing it just yesterday. Now the off duty outfit occupies that slot and the fleet uniform was pushed to a third costume slot which you cannot wear. When trying to wear it you get this slot is not unlocked yet. so now I have to spend credits to modify my uniform that is in costume slot one and lose the one thats there right now just to get my fleet uniform back.
So I lost one of my uniform slots for a off duty set I will probably never wear. I have plenty of credits to pay for the recustomization but still sucks to lose a slot you had to get a off duty outfit without any choice in the matter. I can only hope this is a bug
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