Looks like Nependeaths and Dark Nependeaths are almost never dropping their seeds. Not sure if this is a bug or an intentional change in the code, but it's a huge difference from pre-patch, so I thought I'd make a post anyway.
It is related to this bug: https://royals.ms/forum/threads/nependeaths-dont-all-auto-aggro.87551/#post-461205