Here's how you can make Microsoft Edge remember the pinned state for Downloads, Favorites, Collections and History pop-up flyouts.
Recently, Microsoft introduced the pop-up flyouts for Favorites, Collections, Downloads and History in the Edge app. They now appear as menus. Edge allows pinning them, so they will remain visible all the time. There only problem that the browser didn't remember the pinned state for flyouts, so they used to disappear after you restart Edge. This issues has been finally addressed.