Norton lost from Outlook 2013 toolbar every reboot

Within the last week I'm encountering a new problem with Norton Security v22.5.0.124 and Outlook 2013. The Norton anti-spam toolbar disappears from the Outlook ribbon every time the computer is rebooted. I can get it back by opening the anti-span settings in Norton and clicking on the "Register Addin" link on the Client Integration page. Of course, then I have to rearrange my ribbon to get Norton back where I want it which is an annoyance every day. I've even tried to export Outlook's UI settings and then import them, but that doesn't work either. Does anyone else have any experience with this? I haven't had a problem between Outlook and Norton since upgrading to Norton Security (from ISS) , so it has to be a recent update of either Office/Outlook and/or Norton.

Thanks for any advice.