Not sure which of the many related topics is best for this, but I’m seeing the same reproducible breakage using:
i7-1260P alder lake
Debian 12 - Kernel 6.1
nonfree drivers/firmware on host
Official plexinc container
1.32.6.7468:
HW encode/decode on - Tonemapping on: breaks
HW encode/decode on - Tonemapping off: works
1.32.5.7349
HW encode/decode on - Tonemapping on: works
HW encode/decode on - Tonemapping off: works
Happy to provide detailed logs, sample media, testing on demand, etc - but my logging when seeing issues looks identical to the above post.
Navigate there and download the appropriate package for your distribution (the Debian/Ubuntu 64-bit Intel package, more than likely). Then you can install in the usual way: sudo dpkg -i plexmediaserver_blah_blah.deb