Wiped everything, formatted data in TWRP.
Booted to TWRP. Installed OOS 10 Beta2. Booted to system, configured everything.
Booted to TWRP, flashed magisk stable, booted to system. Installed magisk manager, everything fine.
Booted to TWRP, flashed R194 5-5T OOS and booted to system again...