If you're having issues updating quantities, you can try these steps:
1. Make sure you're using the 'Actions' button at the top of the Products & Variants tab to change quantities.
2. Check your sync settings in the Locations & Integrations section of your settings. Sync should be enabled for inventory quantities.
Still having issues?
1. Make sure quantity tracking is enabled.
2. Check to make sure the Product is 'active.'
3. Make sure that the Product is active at all integrations connected to that location: