Dear @user158496,
This is strange, Could you try with lightdm instead of gdm3 in https://docs.nvidia.com/drive/drive-os-5.2.6.0L/drive-os/index.html#page/DRIVE_OS_Linux_SDK_NGC_Development_Guide/Interfaces/sys_components_file_ubuntu.html#wwpID0E0FB0HA . It worked for customers like here