Hello there!
The KB article below describes how assets are identified uniquely and how they should merge. For your specific case, it depends if your assets are Windows-based or not. This is also mentioned in the KB article.
If you have further questions, our tech support team should be able to assist you with this, please open a ticket in our support portal.
Make sure to add screenshots and the GatherLogs output file so our SME's can start investigating the issue straight away.
Using the GatherLogs tool.