I added two categories with sub-categories from my magento site with multiple websites 2.4.3-p1.
i have imported 100 products assigned products to main category through sheet.
after that created subcategory and trying to assign products to subcategory using admin pannel getting
Unique constraint violation found {“exception”:”[object] (MagentoFrameworkExceptionAlreadyExistsException(code: 0): Unique constraint violation found
i have checked below links
Add categories automatically – Unique constraint violation found
“Unique constraint violation found” Error When Assign Product into Category
“Unique constraint violation found” Error When Assign Product into Category