i think that we must wait for an upgrade of magisk. I don't know why since 20.4 version did not implemented touch screen for cars display unit in last versions..20.4 is good for touch screens and android 10; version 21.4 was good for android 11 and not for touch screens in cars unit.d
The same S2A with APP systemizer in prive-app (only S2A), Magisk 21.4, A11 doesn't work
phone S20U
or you may need to set other applications in the app systemizer ??