After upgrade from Magento 2.2.4 to 2.3.4 the category data not saving. However the category saves correctly and shows the correct saved message. But data inside it not loading.
While troubleshooting I have found in table "catalog_category_entity" if I edit any category Id(entity_id), it shows default attribute_set_id = 0. But the default magento category attribute_set_id is 3(catalog_category).
So while saving category,In table "catalog_category_entity" the value changes for attribute_set_id=3 from zero for a category. And data not showing in admin.
If I revert and change back to attribute_set_id = 0, all category attributes data showing in admin.
Any idea about this type of issue post upgrade to 2.3.4 ?