In the Style Picker, click on the Rebuild button at the bottom and do a Fast rebuild. When that's done, click on the Clear button at the top of the window. Now in the upper left below the Category button it should tell you how many styles are in the list - what is the number?

Also, can you tell us what packages you have? You have 2021 Pro, but have you had any versions before that, or any add-ons?

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