Hello,
thanks for the reply.
well, I had loads of issue in installing a stable working Ubuntu in Thinkpad and therefore also I went through series of problem fixing solutions. In short, there is a higher chance that I played around with Grub, but can not confirm. Besides, I am not much into Grub settings.
Please find the info of my Grub, and guide me further which one I have got and which one I should have [1].
Also, one more important requirement for me is that I am running my work-windows 10 in Oracle VM, that should also be compatible with the Grub.

Many thanks,
pooja


[1]
**************************
pooja@X1-Carbon-6:~$ grub-install -v
grub-install: info: executing modprobe efivars 2>/dev/null.
grub-install: info: Looking for /sys/firmware/efi ...
grub-install: info: ...found.
Installing for x86_64-efi platform.
grub-install: info: cannot open `/boot/grub/device.map': No such file or directory.
grub-install: info: /dev/nvme0n1p1 is not present.
grub-install: info: Looking for /dev/nvme0n1p1.
grub-install: info: /dev/nvme0n1 is a parent of /dev/nvme0n1p1.
grub-install: info: /dev/nvme0n1p1 starts from 2048.
grub-install: info: opening the device hostdisk//dev/nvme0n1.
grub-install: info: drive = 0.
grub-install: warning: disk does not exist, so falling back to partition device /dev/nvme0n1p1.
grub-install: info: /dev/nvme0n1p1 is present.
grub-install: info: Looking for /dev/nvme0n1p1.
grub-install: info: /dev/nvme0n1 is a parent of /dev/nvme0n1p1.
grub-install: info: /dev/nvme0n1p1 starts from 2048.
grub-install: info: opening the device hostdisk//dev/nvme0n1.
grub-install: info: drive = 0.
grub-install: warning: disk does not exist, so falling back to partition device /dev/nvme0n1p1.
grub-install: info: /dev/nvme0n1p1 is present.
grub-install: info: Looking for /dev/nvme0n1p1.
grub-install: info: /dev/nvme0n1 is a parent of /dev/nvme0n1p1.
grub-install: info: /dev/nvme0n1p1 starts from 2048.
grub-install: info: opening the device hostdisk//dev/nvme0n1.
grub-install: info: drive = 0.
grub-install: warning: disk does not exist, so falling back to partition device /dev/nvme0n1p1.
grub-install: info: drive = 1.
grub-install: error: disk `hostdisk//dev/nvme0n1p1' not found.
pooja@X1-Carbon-6:~$ dpkg -l | grep grub | grep ii
ii  grub-common                                                 2.02~beta2-36ubuntu3.19                      amd64        GRand Unified Bootloader (common files)
ii  grub-customizer                                             5.1.0-0ubuntu1~ppa1x                         amd64        Grub Customizer - A graphical Grub2/BURG configuration application
ii  grub-efi-amd64                                              2.02~beta2-36ubuntu3.19                      amd64        GRand Unified Bootloader, version 2 (EFI-AMD64 version)
ii  grub-efi-amd64-bin                                          2.02~beta2-36ubuntu3.19                      amd64        GRand Unified Bootloader, version 2 (EFI-AMD64 binaries)
ii  grub-efi-amd64-signed                                       1.66.19+2.02~beta2-36ubuntu3.19              amd64        GRand Unified Bootloader, version 2 (EFI-AMD64 version, signed)
ii  grub2-common                                                2.02~beta2-36ubuntu3.19                      amd64        GRand Unified Bootloader (common files for version 2)
pooja@X1-Carbon-6:~$