How to use SaveData Manager?

Ejecting my saves doesn't work on multiple games. I back up my data, edit/change my save data, go back, inject, and nothing changes. When I open it up with an editor, the changes are there, so it's a problem ejecting.
old 3DS XL Ninjhax2.0 (Ironhax) 10.1.27
Smash (Physical Copy)
Majora's Mask
Rumble World