I would like to use guide below or in case OneNote is corrupted by unknown reason to use helpful topics below
https://www.repairtoolbox.com/onenoterepair.html OneNote Repair Toolbox
Click the "File" tab above the OneNote ribbon. Select “Info” on the menu and click the "Open Backups" icon in the right panel of the Info section. The software opens Windows Explorer and displays the names of notebook backups stored on your computer. In detail view, this list also shows the date of the last backup for each notebook.
Place your cursor on the name of the notebook that you want to restore and click "Open" in the dialog box to choose the entire notebook. After OneNote retrieves the notebook and its sections, you will see the notebook’s name in the OneNote sidebar.
Restore a section within a notebook by clicking on the name of the folder that contains the section that you want to restore. After the folder opens, scroll through the list of section names to find the one you need. Highlight the section name before you press "Open" in the dialog box. OneNote places the section in its original notebook. To restore several sections, hold the "CTRL" key and highlight each section name to add it to your selections.