This is a known problem, and I have sent broadcast email through knowledgebase@tp-link.com about this issue. If you can't receive the email of our knowledgebase@tp-link.com, please let me know, I'll check the addressee.
For now, please give RMA for customers. From the information we get from the cloud, it may be the MAC address identical problem. The root reason needs to be further looked into.
As to your question.
1. Factory default won't change the message in cloud.
2. This case is a cloud problem, it has been fixed, but now problem device we need to do RMA.