NASP Connected Inventory

I've wanted to like this app as it was an economical way for us to manage inventory shared across several of our gifts, but it keeps changing inventory levels in shop, resulting in several of our products being marked OOS when they really aren't. Even after I change the inventory back to the correct numbers in Shopify, it pulls them out again. It's a never-ending tug-of-war and I'm having to constantly manage and watch our product levels. I'm hopeful support can help, but haven't heard back from them. We tried this app once before and the same thing happened. I had hoped it was a fluke, but perhaps not.