Hi,
The schematic you posted is an example schematic. There is a goid chance that this circuit will work. ;-)
Therefore I assume: not the given schematic is wrong, but your circuit hase some issues.
But we need to see your curcuit. And how you wired it. And what your voltages are. What circuit you used.
--> pictures of your circuit with additional informations.
Like: when the output voltage us only 4.75V...what is your measured input voltage at the same time?
Urgent: read the whole datasheet. (That's what we need to do, too) and carefully follow the instructions, calculations, design considerations, layout considerations..
Klaus