Google Group Migration API "Failed to upload message due to backend error" error while migrating an email

Question

I have been trying to migrate all my emails to a group. I use nodejs google library and I'm the owner of the group. I can migrate between 30 and 40 emails but after of this I have an error where I migrating. I have the next error: { error: { code: 500, message: 'Unknown Error.', errors: [ [Object] ], status: 'UNKNOWN' } } and when I go to see the attribute errors I have the next error:[ { message: 'Failed to upload message due to backend error' } ]

This is my code to migrate:

 const res = await fetch(`https://www.googleapis.com/upload/groups/v1/groups/${email}/archive?uploadType=media`, {
                method: 'POST',
                body:    message,
                headers: { 
                    'Content-Type': 'message/rfc822' ,
                    'Authorization': `Bearer ${oauth2Client.credentials.access_token}`
                },
            });
            const json = await res.json();
            if(json) console.log(json.error.errors);

Any help or ideas will be highly appreciated