[galaxy-dev] impersonation doesn't work in v16.10

I recently installed galaxy v16.10 and have set "allow_user_impersonation = True". However, the impersonation feature seems don't work properly. When I click "Admin->impersonate a user" and choose the account I want to impersonate, and the click "impersonate" button. The page shows "you have login as xxx, return to the homepage". But when I click homepage, the actual login user is still my account. I have been using galaxy v1507 and I have never had any problem with impersonation. I am not sure if this is a bug in v1610 or I just miss something. Ping