Problem with changing variant names and inability to purchase in the store

[TomCzyz]

I have two stores, one in Polish language with PLN currency and the other in English language with EUR currency. Inventory levels between the stores are synchronized in real time through the Multi Store Sync Power application. The main store set in the application is the one in Polish language, from which changes in product inventory levels are transferred, and vice versa, but most orders are processed through the PLN store.

At certain times, especially when adding new products and their inventory levels, there is a situation where variant names, that is, "Size" and "Color" in the EUR store, change to Polish, that is, "Rozmiar" and "Kolor".

In such a situation, after the automatic change, purchases can only be made for the product in one size variant in the EUR store. However, after manually changing the variant names to English, everything returns to normal and purchases can be made for more size variants.

Is it possible to change the admin settings so that variant names are always in English, without having to manually or through CSV change variant names?

I provide the URL of the product from the EUR store with the variant name changed to Polish. 

https://en.nudyess.com/products/accepting-mini-skirt-in-light-melange?variant=43748453187805