Somehow, I thought that Vocabulary Builder data didn't sync between Kindles. Probably because the sync appears to be a little flakey.

For example, my Kindle SE, which I've had for over a year now, didn't have any words associated with the Books listed, or any words I'd looked up on Scribe. And Scribe was the same way and had only a dozen or so words in its Word list.

But I went into Settings and toggled Vocabulary Builder off and then back on. The respective word lists filled out. If that is all it takes to force sync, I can live with it. And I'll be using it more, particularly with foreign language books that I'm attempting to work through.

Just wish the Kindle apps had this feature as well.