I am currently not able to replicate this issue.
Is the subscription sent to Smaily right after creating order and checking the “Subscribe to newsletter” checkbox? Is the same subscriber in the WooCommerce store with subscribed status or unsubscribed status?
The only option for this kind of behavior might happen is when customer subscribes to newsletter after creating an order. From profile settings for example.
Or customer synchronization imports subscriber to Smaily. For example, a customer that made an order and didn’t check the “Subscribe to newsletter” checkbox, but has already been subscribed to newsletter.