Suggested fix (unconfirmed): Use the top-screen labels to guide your search for the notes. For the 5th note, look on the ledge above the entrance doorway in the large chamber with the second Nymph under "The Liberation of the Nymph."
Suggested fix (unconfirmed): Press the 'A' key at the exact moment the prompt appears on the screen rather than spamming it. Alternatively, try to bypass the climbing section entirely by jumping around the rocks.
Suggested fix (unconfirmed): If you use an AZERTY keyboard switched to QWERTY in Windows, remember that the prompted 'A' key corresponds to the 'Q' key on your physical keyboard. Press the correct keys within the small time window as they appear.