I did "diskutil resetFusion", then completely reinstalled Catalina. After initial reboot and restored my account via Time Machine (did not restore application or other stuff), disk seems ok. First Aid on either Fusion or Container were good. But after I install some applications, including Office and Parallels, I got 3 of these warning messages. I did not use Boot Camp. I thought Boot Camp might be the issue. Without doing much on my iMac, I got 8 of these warning messages.