Why chown and chmod -R 777 /my directory does not work

Clash Royale CLAN TAG#URR8PPPWhy chown and chmod -R 777 /my directory does not work
I have tried 2 below command's line:
sudo chmod 755 -R mydirectory from root
chmod -R o+w mydirectory from root/storage
but none of them can change files and folders permission. they could but when the end-user upload a picture the site does not show that.
and the admin(I) have to change permission manually.
what can i do? thanks for reading and answering.
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