Why won't my iMac automatically sign into iCloud unless I open the keychain access application, even though I keep typing in the correct password for my iMac to sign into iCloud?

When I wake up my iMac from sleep, it no longer signs into icloud automatically. Therefore I open system preferences and manually enter the correct password, over and over and it wil not access icloud. . .

However!

If I leave iCloud/System Preference open and then open KeyChain Access (application) and do anything that requires my iMac password (which is different from my iCloud), as soon as I enter the iMac password in and hit enter, suddenly iCloud becomes available at the very same time.

Neither passwords are the same, although I will get an error message stating that they are and it's more of a warning message that it's not a good idea to do that. But, they are not the same.

Do have to seek a Shaman and agree to dancing partially naked under a full moon with my very fat and lumpy body a wigglin' and jigglin' for the all the heavens to abhor?