Using Shared Libraries for negative keywords is more efficient and less error prone than using campaign or ad group level negative keywords.
Using the Negatives section on Squared will resolve this issue and ensure blacklisted keywords are always applied as negatives to current and new campaigns. Load shared libraries straight in at account level.
They can also be applied at group or agency level.
By default, these negatives won't be applied to your Performance Max activity. To find out how to apply these lists (or your own shared libraries) to chosen PMax campaigns check out this help centre article.