Graduation Gown Re-appearing

Product: The Sims 4
Platform:PC
Which language are you playing the game in? English
How often does the bug occur? Often (50% - 99%)
What is your current game version number? 1.84.171.1030
What expansions, game packs, and stuff packs do you have installed? Cottage Living, Eco Lifestyle, Discover University, Island Living, Get Famous, Seasons, Cats & Dogs, City Living, Get to Work, Realm of Magic, Strangerville, Jungle Adventure, Parenthood, Vampires, Dine Out, Spa Day, Outdoor Retreat, Paranormal, Tiny Living, My First Pet, Laundry Day, Bowling Night, Vintage Glamour, Cool Kitchen, Free Stuff
Steps: How can we find the bug ourselves? Unsure.
What happens when the bug occurs? My Sim graduated from University and ever since then, when he changes clothes after a shower it automatically puts him into a graduation gown. I've reset him several times and tried simple fixes but it still happens.
What do you expect to see? Graduation gown isn't an outfit he has saved, so he shouldn't have it anymore.
Have you installed any customization with the game, e.g. Custom Content or Mods? Yes
Did this issue appear after a specific patch or change you made to your system? No

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My Sim graduated from University and ever since then, when he changes clothes after a shower it automatically puts him into a graduation gown. I've reset him several times and tried simple fixes but it still happens.Graduation gown isn't an outfit he has saved, so he shouldn't have it anymore.