Links and attachments are missing when migrating issues from cloud to cloud using excel import

[P Bob Richard]

Hi,

Hope you are doing well.

We are migrating projects and issues from one instance to another from cloud.

When importing Epics, Stories, 

1. The links from Epics to the Stories is removed in the destination site
2. Sub-links are removed in the destination site
3. Attachments are missing are not migration as well

Can you please advise or suggest on how to solve this problem?

Thank you

Bob Richard