@Didgeridoohan Okay, thanks for clarification and referal to didgeridoohan.com. This is a valuable resource.! So I booted to TWRP and tried to mount the Magisk image to remove the Xposed module manually. I've adb sideloaded Mount-Magisk,zip which reports an error: ¨Installing zip file Magisk mounter¨ ¨Magisk is not installed!¨ ¨Updater process ended with ERROR: 1¨. What could be the problem here you think? Neither Magisk Core Only Mode nor Magisk Hide are set to On. Nor does Rootchecker app report Superuser Binary files being installed. The Magisk manager v16.0 itself runs smoothly.
Go to the Magisk general support thread and provide whatever logs you can get your hands on.