Lots of false positives

I’ve been using SpamSieve for many years. In recent months, the number of false positives has increased drastically; I get virtually no false negatives. Any reason this could be? And how to correct it? I looked up ‘false positive’ in the manual and didn’t get much back. I always, always, always “Train as Good” but it doesn’t make any difference even after 20 or 30 or more applications of the command. And these addresses are all in my Contacts. Mail.app 16.0 on macOS 14.6.1; SpamSieve 3.0.5.

The first step in troubleshooting this is to see whether SpamSieve was actually the reason that this message went to Junk. It looks like you had the same issue in 2018 and at that time SpamSieve was not what was classifying the good messages as spam. Please see this page.