Ok, so I found my speed dial bookmarks. I don't use the browser's "Bookmarks" page, I have an extension that I prefer to use, but with it currently gone I found that bookmarks also lists the speed dial.
Now, my speed dial bookmarks all got moved to a folder named after my PC. Because this happened twice, I have two folders.
Not only were they being moved and the default "sponsored" bookmarks put in their place, but the setting to show "suggestions" was enabled, twice.
Very weird. 🙂