We have JIRA and Aha today and the tools are integrated as follows:
For some reasons, I had to delete the integration with JIRA for a specific product line from Aha and thus, lost the link between Aha and JIRA. I could rebuild the links between Aha feature and JIRA Epics as there is a "Link with existing issue in JIRA (Via Connect)" at the Aha feature level.
However the links are lost at the Aha requirement level because I don't have the same button at the requirement level... Even worse, when I rebuilt the integration, Aha pushed the Aha requirements as new JIRA stories in JIRA, although those stories do already exist in JIRA!
I was told by the Aha support team to delete the content from Aha and reimport it from JIRA... but this is a big action that I'm not ready to perform as I'm not sure about the quality of data in JIRA...