The only suggestion I can provide is considering reinstalling windows 10 which means removing lubuntu. The reason for this as a solution is because the system is not recognizing the EFI files even though you are able to see the files on your computer. This could mean the files are hidden (if possible) or not readable by your system. Another option is to contact your computer's manufacturer as they may be able to provide a solution that does not require you to reinstall Windows 10.
Here's an article that provides some information for recovering windows 10:https://support.microsoft.com/en-us/help/12415/windows-10-recovery-options