Windows 8 mail can't sync messages from alias email addres

I have a live.co.uk email address and I added an outlook.com alias, making the latter my primary alias. I noticed that in the Windows 8 Mail app when I selected my Outlook.com account the Inbox showed "Couldn't sync messages". I uninstalled Mail and reinstalled it. The reverse situation is now the case: when I select my Live account the Inbox shows the same message. I think this has only been happening since I updated from 8 to 8.1, but I could be wrong about that. Since I still receive the emails, I suppose it doesn't matter much but I wonder if this should be happening.

Thanks in advance for any help.