What's the output of getprop ro.vendor.build.fingerprint ? You probably need to flash a former OTA version and adjust the offsets a bit. e.g. UP1A.231105.003 or UP1A.231005.007
Edit: The Pixel 6 comes with a different Mali GPU than the Pixel 7 and 7a, THUS WON'T WORK ON THE PIXEL 6. The driver shipped with the Pixel 6 simply doesn't provide the ioctl command that is needed for the kernel address leak. That's also why you will get Operation not permitted when doing Ioctl (KBASE-IOCTL_TLSTREAM-ACQUIRE).
Originally posted by @m4b4 in #6 (comment)