Your system information

• Steam client version (build number or date): Aug 12 2019, at 23:59:32
• Distribution (e.g. Ubuntu): Ubuntu
• Opted into Steam client beta?: No
• Have you checked for system updates?: Yes

Please describe your issue in as much detail as possible:

Actions applied to a user in the chat window apply to all users of that Name/Nickname

Steps for reproducing this issue:

1. Open a chat window with two different friends
2. Set both of their nicknames to "Testing" or something like that (The same for both)
3. Remove one of the users as your friend (Right-click on their chat window icon)
4. Both users appear offline (Except you only unfriended one of them)