Product Variations not showing attributes in title.

Hi Everyone, this is my first post, so please be gentle, I’m not techie at all, but have so far managed to build my store.
However I’m having an issue when I export my product list to CSV – this is to upload to my accounts, but also when exporting a purchase order through ATUM Inventory.
Some of my variable products are only showing the parent title in the Name box, but others are showing the parent title plus the attributes – creating a unique title for each one (I’m guessing this is what it should be doing)

I’ve googled extensively, but can’t find anyone has had this issue.
So far I have tried:
Checking I have the latest updates for everything (I do)
Deactivating all my plug ins (including Atum, I really hope I’ve not lost all that data)
I’ve cleared caches on both my browser page, and my managed wordpress dash board
I’ve checked the set up of the attributes, categories and variations against products that are working fine.
I’ve gone into woocommerce status tools and cleared transients, deleted orphaned variations, and regenerated product tables.

I’ve ben adding products since May without an issue, it seems to have first happened on a product I created on 3/6/19 but it isn’t all products – I don’t duplicate products when creating new ones, each is set up manually – although come to think of it, I have been creating the variations, publishing the product, exporting it to csv, adding most of the price and sku information before importing it back in to the product, then I have been going back through the variations to input the Atum Inventory data – Nope, just deleted the variations on one of those, manually did all the variations, still not showing on the CSV correctly.

Has anybody got any ideas on how to sort this without having to delete the effected products and re-do them (not that I’m sure this will correct the issue)?

Thank you, Rebecca