Paperwhite fonts adding random dashes/hyphens

[Siavahda]

I just got the 2018 Kindle Paperwhite, but this was the case on my previous model (2015) as well: it doesn't happen in every book, and it only happens at font size 1, but sometimes at the end of the line the Kindle inserts what I've been calling a 'fake hyphen' - it doesn't look like the hyphens that are part of the actual book, and it's placed where there should be a space between words. Not when a single word is running over onto a second line, which would make sense.

There's a space, then this mini/fake hyphen, then another space, all at the end of the line. The sentence continues normally on the next line. I first assumed they were typos, but there's nothing in the ebook files, and a quick Google turned up some mentions of Bookerly and hyphens from when the font was first introduced.

However, some testing reveals that the hyphens still appear with Caecilia and Palatino. Baskerville size 1 doesn't have them, but jumping up to size 2 brings them back. So I have no clue what's going on, basically.

I'll bite the bullet and just switch preferred reading fonts + sizes if I have to, but does anyone have an idea what's causing this and how to make it stop?