Try this from an ADMIN command prompt
bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi
Note: This is from Windows 10, and this will work with any flavor of Ubuntu and with Mint, it will not work with other distributions.
Friendly Consulting
Try this from an ADMIN command prompt
bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi
Note: This is from Windows 10, and this will work with any flavor of Ubuntu and with Mint, it will not work with other distributions.