The issue you're encountering with systemui looping or crashing after the latest release on KernelSU 11874, LKM, and Pixel 6 is a known problem that has been reported by several users. Systemui is a critical component of Android that manages the user interface, and its malfunction can lead to various issues such as the infamous 'XXX app has stopped' error. This error typically indicates that an application has crashed unexpectedly. KernelSU is a popular custom kernel for Android devices that offers additional features and optimizations. However, like any software, it can have bugs or compatibility issues with certain device models or software versions. In your case, the latest release of KernelSU seems to have introduced an incompatibility with systemui on your Pixel 6. To resolve this issue, you can try the following steps:

  1. Update KernelSU: Check if there is a newer version of KernelSU available that addresses this issue. Sometimes, developers release patches or updates to fix known bugs.
  2. Revert to Previous KernelSU Version: If updating doesn't help, consider reverting to a previous version of KernelSU that was known to work with your device.
  3. Check for Device-Specific Fixes: Sometimes, device manufacturers or the KernelSU community release device-specific fixes. Check if there are any custom ROMs or mods for your Pixel 6 that address this issue.
  4. Report the Issue: If none of the above solutions work, consider reporting the issue to the KernelSU development team. They may not have a solution yet, but reporting the issue helps them identify and fix the problem in future releases.
  5. Wait for Official Fixes: Finally, if the issue is a known bug, it may be addressed in future official updates. Keep an eye on KernelSU releases and updates.

Remember to always backup your data before attempting any of these steps, as they can potentially affect your device's functionality.