Is this on a desktop computer?
A laptop very often has a low powered card that is used for initial vga mode to boot grub etc, and then only switches to discrete GPU (in this case Nvidia) if it detects that mode is needed (powersave, inbuilt GPU is default, high power discrete GPU for 3d acceleration etc)
nomodeset will boot it using inbuilt GPU so you might have to ‘force’ Nvidia mode only..
This is Ubuntu, another Debian based distro so same process;