Update: the stock status seems to be defined by the stock of each product at the product level in woocommerce – not at the variation level.
Let me explain more in details: in Woocommerce, the stock level of a variable product can be defined at the global product level (for instance 18 t-shirts altogether) or at the variation level (for instance 10 t-shirts in size S, 3 in size M, 5 in size L).
When we manage stocks with ATUM, stocks for a variable product can only be managed at the variation level (which makes more sense to me). But it seems that the stock status of each variation is defined by the stock level of the global product in woocommerce. By default, this stock level is 0, which probably explains why all products were out of stock in the store in the case of tmh23.
If I change the stock level of product to non-zero in woocommerce, it becomes ‘in stock’, as well as all its variations.
In ATUM there is also the problem that the filters ‘in stock’ and ‘out of stock’ are affected by this problem. If all my products have 0 quantity at the product level in woocommerce, then all my products and products variations will be ‘out of stock’ in ATUM, even if the stock levels of the individual variations are non zero.
So as it is, the only way to manage my stocks in ATOM is to expand all products to show all variations and look at which ones are 0 and which ones are not. I cannot use the filters and get a summary of in stock/our of stock products.
I hope this is clear, let me know it you need more information.
Thanks!