Very difficult to comment based on your supplied info. There could be many factors for an increase or decrease in FII / DII holdings. Ultimately they are also investors like you and me for the same reason (to make money).
Try to post your…so called fundamentally strong growth stocks so that people can comment on it.
Many hypothetical reasons may arise, DII and FII investment, both have their pros and cons.
Share your script list then we could help or learn you with.