Something from a Debian mailing list:
I found the root cause, when testing 6.12.57 I installed the image then the headers and the NVIDIA DKMS module was not rebuilt because the matching linux- headers package was not installed at the time the kernel image was configured.
If I install the headers first and then the linux-image package, DKMS correctly builds the NVIDIA module and 6.12.63 works fine, so it doesn't look like a kernel regression after all.
I don't know if I should manually run dkms autoinstall myself after a kernel update (I never had to before) or if there was a bug during the install process of this update.
Makes sense, I had NVidia compile fail in a similar. This makes it obvious what I should have observed.
