This if for POCO update 11.0.4 Q (Jan 22)
Follow if installing Magisk causes issue
Ok buckle up buckaroos. I think I got it. Magisk 20.0 does work. But not if you have old magisk stuff set up.
So steps:
1. install latest MIUI (eu) as you normally would.
2. Use magisk uninstaller. All your magisk files and configurations like audio stuff will be gone but hey, this is the way. I did this twice.
3. Boot into system. Make sure everything is good. If not. Repeat 1 and 2 again making sure to wipe cache and dalvik and optionally system before flashing stuff. Reboot to recovery and then into system.
4. Once you're sure that everything is working go back into recovery. Flash Magisk 20.0 (find using simple Google search). I did not wipe anything at this point but you could try if you'd like.
5. Boot into system.
6. Set up all of your root apps again :'(
7. [Optional] upvote my comment if successful. I live off of spite and fake internet karma
I have spoken.