Hi oushammour
So that's the latest one. Very weird...
I wonder if this is a conflict with the new version of WooCommerce!
Absolutely not because I've just tried it locally myself (with the latest WooCommerce version) and it's working as expected for me.
But perhaps it could be some kind of conflict with any 3rd party plugin. Might you try to disable all your plugins except WooCommerce, ATUM, and Multi-Inventory and try again, please?
Best Regards,
Salva.