I installed Office 2016 (64 bit) right after it came out. For two weeks or so I have been prompted almost daily to install important updates which turn out to be for Office 2013; of course they fail to install. How can I stop this, and if there is any update for Office 2016, how can I get those?

Recently I am also frequently prompted to install important updates to Windows Defender which fails to install too. I run Bitdefender which probably turns off Windows Defender. However, I have run BD for years and have this issue with the updates only in the last two weeks or so. How to resolve it?