Chrome Version:  71.0.3565.0/11116.0.0 dev channel Daisy,Kip and Reks
OS: Chrome

Pre-condition : Add 4-5 Users

What steps will reproduce the problem?
1)Sign in to user-> logout -> sign in to another user-> Go to Uber tray -> click on user I'd and select 'Sign in to another user...' option for Multiple sign-in
2)Add upto 4 users for Multiple Sign-in -> Now at Uber Tray click on 'Collapse Menu' icon so that Uber Tray collapses 
3)Now click on Profile picture and observe unable to scroll down for remaining users to view and even on pressing 'Tab' also focus will not be seen on remaining users 
(Please refer Video)

Expected: Scrollbar should be seen to view remaining users
Actual: Instead No scrollbar is seen 

This is Non-Regression Issue as New Uber Tray UI is seen from M-70