Before Start!

Make sure the bug also happen when Details! is the only addon enabled.

Game and Details! version
Details! Version: VWD 12109 RELEASE 10.2.0

Describe the bug
Nickname only appearing in Damage Done

Noticed this started happening sometime before 10.2 launched.

Screenshots
Images

You are using an addon to add things to your nicknames. Disable or uninstall those and test again.