Not strictly SpamSieve, but my mail Mac Mail spam filtering rule (my own, not SpamSieve’s) has gotten shortened. I had more than one screen of conditions, and now only one screen is showing. My rule contains a condition that is cutting off a sender I now wish to restore, but that condition no longer shows on the one screen I can now see.
It may just be a display issue. Have you tried scrolling down the list of rule conditions? (The scroll bar may be invisible when you’re not doing a scroll gesture.)
Alas, that’s not it. Tried everything to get it to scroll.