How to change the homepage to phone version back?

It should be at the top and say something like updated version (if I read you question correctly)

Actually I was wrong go to your pfp in the top right and in the drop down it should say mobile version

Go to the very bottom of the page. I think you will see a mode that says "mobile version" and when you click on that, you will be back on the phone version. I hope that helped... ٩(๑❛ᴗ❛๑)۶

Ahh thank you!