OK gotcha. The way the guides I've read have worded it left that unclear in my eyes. Thank you.Same here, Just entered the game again.
You cannot flash any modified Image without unlocking the bootloader. While the bootloader is locked,, You can only flash stock firmware direct from ODIN. Whatever modified partition you flash will trigger and trip the knox. Thereafter SamsungPay, SamsungHealth apps will refuse to work.
Interestingly, I just received an OTA notification too. Rooted / SD with Magisk not even hidden.
I got a notification for the March OTA.