This had become an even bigger issue for me. In the past - I could ask for a user to share their password with me - which I did not like - but they would. Then I could log in as them and see exactly what they are seeing - versus what I see from my Super User Account.
It seems that Hubspot has implemented an additional layer of security - which is good - but causing me more pain.
Now - even if I have user name and password - I now also get the Hubspot Code - which is sent to the user.
This needs to be addressed sooner rather than later. It is next to impossible to support a large team and do the appropriate testing - when I cannot impersonate a user.