SKUs being labeled unique, but still get the error message, cannot save.

I have cleaned out all of the old SKUs and variations. I go in and enter a new SKU, the plugin tags it as “unique” and when I go to ‘Save Changes’ the website spits out the error message ‘Variation SKU must be unique’. I do not know how to proceed with this, can you please provide me with some assistance. I would very much appreciate it.

Kind Regards,

Deeperblue