If autocorrect is not working in either Microsoft Word or OneNote on your MacBook Neo, even after checking the settings, the next step is to determine whether the problem is with macOS’s built-in text correction or Microsoft’s own spelling and editing features.
These systems have separate settings, so enabling autocorrect in one does not necessarily enable it in the other.
First, open TextEdit, create a new document, and type a deliberate misspelling such as “teh” followed by a space.
If macOS changes it to “the,” autocorrect is working in that app, and the problem may be specific to Word and OneNote.
If it does not, the issue may be system-wide.
In Word and OneNote, click inside a document and check the menu bar for Edit >> Spelling and Grammar >> Correct Spelling Automatically.
If this option is available, make sure it is enabled. Apple explains how to manage this feature in its guide to correcting spelling on Mac.
In the desktop version of Word, also open Word >> Settings (or Preferences) >> AutoCorrect and ensure that Replace text as you type is selected.
This is separate from macOS’s autocorrection setting. See Microsoft's instructions for turning AutoCorrect on or off in Word.
For OneNote, open OneNote >> Preferences >> Spelling and check that Check spelling as you type is enabled.
If misspelled words are underlined in red but not automatically corrected, spelling detection is working, but automatic replacement may not be.
Microsoft provides further instructions in its OneNote for Mac spelling guide.
Also check that Word and OneNote are using the correct proofing language for your text.
Then save your work, quit both apps completely, reopen them, and test again.
If the problem persists, restart your Mac and check for available updates to macOS and both Microsoft apps.
I would avoid resetting system preferences or reinstalling Office until these checks have been completed.