Try it with a different magisk, i have this problem as well before, when the loading is stuck at 0% then 9% then 19%. You can download it from chrome or other browser. Download magisk v26-1 then try it. Trust me, it'll work. Hope it helps.
If it doesn't work for some of you guys, try installing different magisk, search on chrome and type magisk download, and choose v26-1 and if your phone is not root, download vphonegaga gold mod vip, then try it, it work fine for me, the problem is the magisk! The one from here doesn't work on...