Here is a very re-producible bug/problem, due to context and complexity.
Take any product in a shop with a custom fulfillment service, more than one location and go to setup. Imagine you have set for a custom fulfillment service in the Inventory Management select. Fine. Way to go. Now imagine you decide for whatever reason to switch that Shopify for inventory management. Way to go. Fine. Note how Shopify just changed the whole context of inventory to be location aware, since with Shopify, you manage inventory by locations.
Ok... so now Edit your Locations and a modal comes up, allowing you to change locations. Hit Save. You get a nice Toast message telling you Saves were done, but the Dialog no longer just goes away.
That is because when you changed inventory management dropdown, and did not hit save, Shopify did a bunch of context things, leading you to believe you were good to go. But you were not. Failure to Save that drop down change results in a mess, and that modal does not self-disappear.
Yes, this is a complex beast. And no, it is likely not easy for the programmers to see that, but it is a PITA , and so this is a PSA alerting Shopify to the problem. Call it a bug, or not, I could not care. I just know this is wrong... either don't lead me on about the context when I change that dropdown, or inform me upon saving the location changes that you will also save the inventory management. Otherwise, confusion reigns.