Please do not upgrade to kernel 6.1.0-18-amd64 right now. There is a known issue with non-GPL variables during compilation, and the DKMS driver does not compile on this kernel.

Please check the thread at NVIDIA for more info:

https://forums.developer.nvidia.com/t/l … /280908/66

Purging kernel-image-6.1.0-18-amd64 and kernel-headers-6.1.0-18-amd64 keeps the earlier version, solving temporarily the issue:

apt purge linux-image-6.1.0-18-amd64 linux-headers-6.1.0-18-amd64
apt upgrade
apt autoremove