WooCommerce Completed Order Email Not Sending (Including Test Email)

I am experiencing an issue with the WooCommerce Customer Completed Order email not sending.

The issue:

Customer Processing Order emails send successfully.
Customer Completed Order emails do not send when changing an order from Processing → Completed.
The order status change is recorded correctly in the order notes.
The Completed Order email preview works correctly.
The Completed Order email also fails when using the “Send test email” option in WooCommerce email settings.
The Resend Completed Order Notification action from the order page does successfully send the email.
SMTP is working correctly, as other WooCommerce emails send without issue.

I have verified:

Completed Order email notification is enabled.
WooCommerce email settings appear correct.
The email template is loading correctly.
No custom snippets are affecting WooCommerce email functionality.

I am using the WoodMart theme with WoodMart Core and wanted to check if there is any known conflict affecting the WooCommerce customer_completed_order email trigger or email class.

Could you please advise if WoodMart/WoodMart Core has any known compatibility issues with WooCommerce Completed Order notifications?

Thank you!