Hi @Andrew_Jaanuu,
In checkout (for performance reasons), app metafields may be provided after the initial render of your UI extension in some cases. As long you subscribe to the change (like you are doing using useAppMetafields()), this impact is usually negligible. We are aware of this quirk though and understand it can be difficult to act on the state of checkout when you aren’t sure if you have the resolved app metafields or not. We do have plans to address this, but we don’t have any further details to share at this time.