Sorry if this has been covered before, and also I know this is not SpamSieve’s fault — I’m just hoping someone has some advice.
My symptom is that Apple Mail keeps resetting its rules. So, I delete the Apple News rule and create the SpamSieve rule, moving “all” messages to All Junk. Works fine. After a while (perhaps after restarting the computer?) I come back and SpamSieve is mysteriously not working at all — except that it’s no mystery, because Apple Mail has deleted the SpamSieve rule and has re-created the Apple News rule. Why, Apple?
More info: This is a new M1 machine running Monterey. I copied the SpamSieve prefs and account settings as explained in the manual, in order to keep my training data from the old machine (that part is working fine, so long as the SpamSieve rule is actually present).