I love my things being well organised, sometimes i could open as many as 20+ tabs making it really difficult to navigate from one to the other. Apparently, the recent version 5.1 lollipop got the Google Chrome tab stacking feature all wrong. There is definitely a way to go round this feature by disabling tabs and recent apps merge in Google Chrome through its settings as shown below..
Step 1
Step 2
Next is to Turn it off and confirm your choice when prompted by tapping OK. As much as i hate this feature in Android 5.1, the steps above should help return your smart device back to its old tab arrangement on Google Chrome. Share if it helped!