Every time I reboot my computer, Today Summary and Tomorrow Summary re-add themselves to my Notification Center. I remove them (click Edit, click the red block button, click Done), and they only stay removed until next reboot.
I'm the only user on my machine. My account is admin. I sync with iCloud, but I don't use these widgets in iOS either, and they don't re-appear there ever.
Is there perhaps a pref file I should trash, or a cache I should reset?
MacBook Pro macOS 10.12.5 Sierra