How to remove old device from Safari iCloud Tabs?

I returned a MacBook to Apple Store, however apparently I forgot to sign out of iCloud and the latest tabs I was browsing still appear in Safari iCloud Tabs of my new MacBook and existing iPad. I removed the device from icloud.com -> Find My iPhone but it didn't work. Tabs list from my old computer is still there and I am trying to remove it from my devices list. I appreciate any ideas.