editing not working meta fields

when adding meta fields with attributes, they are empty and do not display information.
On your demo site, for example, if you select the attribute_pa_size meta field for the “Abstract Print Cotton Blouse” product, it will be empty. Although the attribute of this field is filled.

Please tell me how to fix it. I specifically bought your plugin for meta fields with attribute editing, but this function does not work.

I just need to bulk change certain product attributes without opening a separate modal window for each product to change the attribute.

Thank you in advance.