Facebook scrolling issue on MacBook Air

Hi 5885-,

Thanks for posting in Apple Support Communities.

If the issue occurs only on FaceBook, reload the page and then force quit the site and open it again.

"Check Safari extensions

If you installed any Safari extensions, make sure that they are up to date.

You can also try turning extensions off. From the menu bar in Safari, choose Safari > Settings (or Preferences). Click Extensions, then deselect the checkbox for each extension to turn it off. Learn more about Safari extensions. 

Check Safari settings

The webpage might not be compatible with one or more browser settings, which you can turn on or off as needed. From the menu bar in Safari, choose Safari > Settings (or Preferences). Then click Websites, Privacy, or Security to access these settings:

• Websites settings. These settings can be configured for specific websites.
• Privacy settings. These settings apply to all websites.
• Security settings. These settings apply to all websites. 

Test with a private window 

A website can store cookies, caches, and other data on your Mac, and issues with that data can affect your use of the website. To prevent the website from using that data, view it in a private window. From the menu bar in Safari, choose File > New Private Window, or press Shift-Command-N.

If that works, use the following steps to remove the website's data, including its caches and cookies. The website can then create new data as needed. If it's a website that you sign in to, make sure that you know your sign-in information before continuing.

1. Choose Safari > Settings (or Preferences), then click Privacy.
2. Click Manage Website Data.
3. Select the affected website from the list shown.
4. Click Remove.
5. Click Done.
6. Open the website again in a non-private browser window."

You can find these and additonal steps in If Safari on Mac doesn't open a webpage or isn’t working as expected.

Regards.