Hi submedia ,
I think you misunderstood my words.
Sorry, I needed to activate both options at the same time.
You only have one active. As I wrote, that way works as it should on my side. Then, one third-party plugin or code customization may be interfering with Multi-Inventory.
Before going further, you need to find it. Please try deactivating all your plugins except ATUM-related ones and WooCommerce and switching to a default theme like Storefront. If the problem disappears doing this, you can reactivate your theme and plugins one by one until the issue reappears.
If it doesn't disappear, perhaps the problem is with some kind of server cache. Please try to disable it and check if the problem is fixed.
We'll be waiting for any updates from you.