Try this:
1. Click on SETTINGS (it’s at the top of the page).
2. Look to YOUR left. Scroll down to MY ACCOUNT and click on GENERAL SETTINGS.
3.. Scroll about ½ way down the page until you find THREAD DISPLAY OPTIONS.
4.In that section look at Thread Display Mode. Make sure it reads Linear-oldest first. If it doesn’t click on the little blue square until you find that option and click it.
5.Scroll down to the bottom and click SAVE CHANGES.
Hope this helps.
Hope this helps.