Product CSV upload is auto-creating product variants I don't have listed

I’m uploading a client’s CSV of 982 product variants for the Webflow ecommerce store. After much trial and error, I’ve finally got it uploaded with no errors, but now I’ve noticed that even though when I upload it and it tells me “131 products with 982 variants uploaded,” I see that there are actually 1143 total product variants created (which shouldn’t even be allowed given the plan we’re on only allowing 1000 max variants). What I saw that Webflow was doing was automatically creating a variant of a product, just because it was a unique combination of the options.

For example, if the store offers a shoe in four colors and ten different sizes, Webflow is automatically creating 40 variants (4 x 10), even when there are only 27 total variants (some colors are not available in certain sizes). Then Webflow just randomly copies the SKU of one of the other products and pastes it in the SKU column of the new variant it creates. Not a very good system.

Is there a way to not have this happen? I tried JUST uploading the single product with its 27 variants, and it successfully only created the offered variants. However, with 131 items, this is not a time-effective solution/workaround.