Failed to Store usually means that the item is corrupt, too big or something else internally has occured on Storage Archive within EV
Failed to Expand DL tends to be when the EV account doesn't have access to a Distribution List to pull the names from OR the DL no longer exists (sometimes seen when you pull legacy PST files to journal or you are journaling someone elses mail)
Failed to Copy usually means the item is out and out right corrupt or it has a damaged P2 message etc
The only thing i can suggest is the Failed to Expand DL is to switch a policy option so that if it expands DL it still archives it regardless, but when you search you will have to search by the DL name and you won't know who really received it (but if its a case of the DL doesn't exist, you wouldnt know this anywho)
https://www.linkedin.com/in/alex-allen-turl-07370146