Windows Defender nagging me

Does anyone on the forum use Windows Defender as their antivirus protection? I've always had Real Time Protection enabled under Settings, and it never issued any sort of message about doing manual scans. However, since January 2 of this year it has started pestering me to do manual scans, sometimes twice a day. Did Microsoft, in their infinite wisdom, decide to alter something via one of their updates? I've searched for a way to disable this but no luck so far. I really hate it when they decide what's best for me instead of just leaving me to my own fate.

I use the program, and it's current as of today. Nag free.

Are you cleaning the Win Defender logs, which the program may rely upon to determine if a scan is needed? I don’t.

Thank you kroozer, as usual, you are correct. I did have it ticked on under Utilities. But solving the problem reveals a mystery. I downloaded and installed CCleaner v. 4.09.4471 on 12/20, the day after it became available. I went through all the settings, made my usual selections, and haven't changed anything since then. So from 12/20 until 1/1, no problems. Starting 1/2, the messages from the Action Center start popping up. I've unticked it now, so I'll keep my eyes on it and see if anything changes. BTW - I like the new avatar, a new look for the new year.