Kerns, could you explain a bit more about how you "can't make it work for a single inventory per item"? Is that a limitation for your business or a problem/limitation with shopify's POS? That is the main reason I was looking to move into using their POS, because we sell online and in store from one inventory, and I wanted both sales channels (in store and ecommerce) to use 1 single shared inventory.
Hello Kerns, are you updating inventory via product import csv. If so, it doesn't work anymore. Try updating via inventory csv in inventory section it should work fine. We had the same issue and this how we sorted it out. Please do let me know if you need any further help.