LMDE only supports up to NVIDIA 535.
You need to update to a newer release, I had to do the same 2 days ago.
As of right now the only way to update to the newest nvidia drivers on LMDE or other Debian Bookworm releases is to use the official installer from the nvidia website.
Put the installer in your root directory, blacklist nouveau, kill X/Wayland (stop lightdm to make sure it stays dead). As root from a TTY:#/nvidia*.run to run the installer, follow the instructions and READ CAREFULLY, if your system is not correctly configured at time of install, it will tell you, but will allow you to proceed anyway, don't. Once all is done, verify your initramfs is good, and if you have a dual-GPU system (most gaming laptops for example) you should restore your xorg.conf from the backup the installer made.
Happy sailing, good luck ๐ซก
(Edit for clarity, I know this sounds like its an unrelated fix but it fixed this exact issue for me with Kingdom Hearts 3+Re-Mind