Hi,
What is the change you made? Am I right that:
A) You copy the project to the new location on thy system level => This cause the problem.
B) You save the project from Nuendo 7 to the new location => This works.
Am I right?
How did you save the project? Did you really just save it or did you use the Back up Project function?
Could you share a small example of the project, please (both, copied, and saved)?
What OS do you use? Mac/Windows? How is your drive formatted (FAT/NTFS/APFS)?