Thanks a lot @Junior Passos
Feedback (25 Jul 2019): Worked like a charm with twrp-3.2.3-0-albus.img and Magisk-v19.3
:good::good::good:
How to Root Stock Oreo:
1- Boot in TWRP;
2- Go to Backup > mark Boot and System partition > Swipe to backup (don't needed system_image);
3- After this, go to Restore > select Boot and System > Swipe to restore;
4- After finished, install zip Magisk (17.1 or 17.3);
5- Reboot and DONE!!!
Feedback (25 Jul 2019): Worked like a charm with twrp-3.2.3-0-albus.img and Magisk-v19.3
:good::good::good: