If there is an infinity sign ∞ as your stock level for your variants, this indicates 'Manage Stock Level' was unchecked when creating the product on QuickBooks Commerce, or the product has been imported from your Sales Channels as such.
Shopify's equivalent setting to 'Manage Stock Levels' is 'Inventory Policy', while on On WooCommerce is 'Manage Stock'. If the setting for the product is disabled on the Sales Channel during import, 'Manage Stock Level' will be disabled on QuickBooks Commerce and will be reflected with an infinity sign.
If you need to update this setting in QuickBooks Commerce, please reach out to our Support team and they will be able to help you with this.