Salesforce Users Assigned With The Same Page Layout Sees Different Related Lists

When not all users see the same Related Lists, this happens when users have customized their personal Related List settings.  The following instructions show ‌how to override all users' personal Account object Related List setting.

In Salesforce Classic

1. Go to Setup
2. Under "Customize" section, click on Account object.
3. Access the Account page layout.
4. Remove any related list from the page layout (for example, Notes) and drag it back to the palette.
5. Click Save.
6. Access the Account page layout again.
7. Place the previously removed related list (for example, Notes) on the page layout.
8. Click Save.
9. On the “Save page layout changes?” pop-up, check the box for “Overwrite users’ personal related list customizations with my page layout changes.”
10. Click Save.

In Lightning Experience

1. Go to Setup
2. Click on Object Manager
3. Go to the Account object
4. Access the Account page layout.
5. Remove any related list from the page layout (for example, Notes) and drag it back to the palette.
6. Click Save.
7. Access the Account page layout again.
8. Place the previously removed related list (for example, Notes) to the page layout.
9. Click Save.
10. On the “Save page layout changes?” pop-up, check the box for “Overwrite users’ personal related list customizations with my page layout changes.” 
11. Click Save.

Note: The above steps overwrite all Users personal Related List customizations that are using that particular page layout. This is applicable to all objects.