What makes you say that the score is less than 99? We discussed this before here and here, and that was not the problem. It had nothing to do with the blocklist. Rather, the issue was that SpamSieve was not looking at the messages at all because your server junk filter had moved them out of the inbox before they got to your Mac. The solution is to use the rescue script, as I suggested to Carrickp.
If you have SpamSieve configured to move blocklisted messages to the trash, that’s what the regular Train as Spam command will do. You also set up a TrainTrash and script mailbox yourself. I think that’s more complex than what most people want, but it’s fine to do that so long as you only use it for messages that were already moved to Junk automatically.
Did you ever investigate that as previously discussed?