Kindle paperwhite 4 vocabulary builder problem

Hi everyone, I've recently bought a kindle paperwhite 4 (upgrade form the previous generation because of the bigger memory and water proof). After using the new kindle for a while I found something odd on my kindle.
with my older kindle and even with the review videos of the kindle paperwhite 4 I've seen on Youtube, you can find the vocabulary builder function under the ... drop down menu on the home screen (the 1st picture)
But for my own kindle I can't seem to find it (as you can see in the photo I've attched)
I can only find vocabulary builder when I'm inside a book. (photo 3)
I wonder if that's just the new kindle or mine is not working properly. I've tried to restart, reset my device. even contacted customer service on Amazon but he/she can't fix my problem (or take it seriously). Is your kindle paperwhite the same or you can find the vocabulary builder when you're in home screen?

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