name change causes issues when opening chat window

Description:

People are trying to open a chat with one of our colleagues that recently changed their surname - "J. Schulte" became "J. Kuettner"
People that never have had any chat contact with him before don't have any problems finding him and opening a chat window.
However people that have had contact before experience 4 different phenomenons:

1. if they search for example for "jku" and click on "kuettner" the chat tries to load a window, but nothing happens and the app freezes.
2. if they search for "jschulte" the chat window still appears (as they had contact before) and they can reload the window, but they are chatting with jschulte (an account that shouldn't excist anymore)
3. some people even click on jschulte but it opens a window with jkuettner
4. it says "jschulte" above the chat window and int the contact list but above each message it says "jkuettner" and the time.

Expected behavior:

Clicking on jkuettner should open a chat window with jkuettner, even if people had contact with him under his previous name.

Actual behavior:

see "Description"

Server Setup Information:

• Version of Rocket.Chat Server: Version 0.65.2
• Operating System: Debian 9 Kernel 4.9.0-6-amd64
• Deployment Method: extract .tgz and npm install
• Number of Running Instances: 1
• DB Replicaset Oplog:
• NodeJS Version: 8.11.3
• MongoDB Version: 3.2.11-2

No files, tests, or entry points are named. Start by reproducing the surname-change scenarios on the reported Rocket.Chat 0.65.2 setup, then trace chat and contact lookup behavior for users with prior conversations; done means each selection opens the current J. Kuettner chat consistently without freezes or stale names.