Potato Leek Soup Separated

Hey all, made this recipe last week: https://www.seriouseats.com/best-potato-leek-soup-recipe

And it's delicious, but we also noticed that the soup was very thin, and then it turned out that the riced potatoes we added back in didn't really blend with the stock so much as sink to the bottom. The recipe didn't really explain how to reincorporate them, nor how long to simmer after doing so, so I'm wondering if we just mistimed something?

Again, it tastes great, it's just kind of annoying that it has to get stirred up a bunch when you go in for a bite.