dual boot no longer working correctly

[kalpana]

I'm new to posting here, please forgive me if this is not the correct place.

I had an Ubuntu / Windows dual boot system that was working well until I tried to set up SSD external drive to boot and run Ubuntu. I made sure to add the BOOT info to the /dev/sdg of the SSD drive so as not to upset the current boot loader, but it seems to have upset it anyway.
I can no longer boot up and run Ubuntu unless the SSD is connected. If I disconnect it and try to run Ubuntu, it stops on the #grub prompt. However, if I boot up and do nothing, Windows will load.

I've tried disconnecting the external SSD after booting up on my original Ubuntu on the PC, and then running grub-install, but that hasn't fixed the problem.

How can I restore the original grub state so as to have it work normally as a dual-boot when the external SSD is disconnected?

I have two NVMe drives installed and Ubuntu and the EFI that I use are on nvmen1p1 drive.

Here's the relevant contents of the pastebin:

Thank you so much if you're able to help me with this.
Code:

Code Select Expand

nvme0n1p1: _____________________________________________________________________

    File system:       vfat
    Boot sector type:  FAT32
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System: 
    Boot files:        /efi/BOOT/bkpbootx64.efi /efi/BOOT/bootx64.efi
                       /efi/BOOT/fbx64.efi /efi/BOOT/mmx64.efi
                       /efi/ubuntu/grubx64.efi /efi/ubuntu/mmx64.efi
                       /efi/ubuntu/shimx64.efi /efi/ubuntu/grub.cfg

nvme0n1p2: _____________________________________________________________________

    File system:       ext4
    Boot sector type:  -
    Boot sector info:
    Operating System:  Ubuntu 23.04
    Boot files:        /boot/grub/grub.cfg /etc/fstab /etc/default/grub

nvme0n1p3: _____________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows 8/10/11/2012: NTFS
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System: 
    Boot files:       

nvme0n1p4: _____________________________________________________________________

    File system:       swap
    Boot sector type:  -
    Boot sector info:

nvme1n1p1: _____________________________________________________________________

    File system:       vfat
    Boot sector type:  Windows 8/10/11/2012: FAT32
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System: 
    Boot files:        /efi/Boot/bkpbootx64.efi /efi/Boot/bootx64.efi
                       /efi/Boot/fbx64.efi /efi/Boot/mmx64.efi
                       /efi/ubuntu/grubx64.efi /efi/ubuntu/mmx64.efi
                       /efi/ubuntu/shimx64.efi /efi/ubuntu/grub.cfg
                       /efi/Microsoft/Boot/bootmgfw.efi
                       /efi/Microsoft/Boot/bootmgr.efi

nvme1n1p2: _____________________________________________________________________

    File system:       
    Boot sector type:  -
    Boot sector info:

nvme1n1p3: _____________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows 8/10/11/2012: NTFS
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  Windows 8 or 10
    Boot files:        /Windows/System32/winload.exe

nvme1n1p4: _____________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows 8/10/11/2012: NTFS
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System: 
    Boot files:       

nvme1n1p5: _____________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows 8/10/11/2012: NTFS
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System: 
    Boot files: