We have different users using Jira Service Desk and Azure DevOps. When comments are added on the JSD side, they get synced to Azure and are added to issues using the account that generated the PAT (mine).

When comments are added to Azure, they get synced back to JSD and added using a admin account (Service Desk Admin).

When sync is triggered from Jira Service Desk at a later stage, any existing DevOps comments that were synced back to JSD from DevOps in the past (and showing as added by 'Service Desk Admin') are attempted to be synced back to Azure DevOps. As the original comment in DevOps was added by a real person(!), as opposed to Service Desk Admin, Exalate tries to edit the DevOps comment. But as the comment was added by another user, it won't allow the edit.

A bit of a tricky one to explain, but hope that makes sense! In an ideal world, Exalate wouldn't even try to update the original comment from the past and only looks for new comments.