I have a galaxy s20 exynos version. I use my edge screen for apps all the time. As you may know: the battery life on the Exynos version is depressing. So I went to a Samsung service center. The told me to do a factory reset of the device.
Since I did the factory reset, I seem to be unable to add certain apps to the edge screen. Like Netflix and tetris. These apps are simply not in the list as shown in screenshot. Before the factory reset, I was able to add these 2 apps just fine.