Correct twice displayed key in the list?

[WOLS]

After changing from Task to Epic, an entry is listed twice:

The epic is clear and fully usable, but I'd like to correct the view.

Thank you for every hint!

[Alex Koxaras _Relational_]

Hi @WOLS and welcome to the community, 

The reason this is happening is because there is still a value on the epic link of the Epic (formerly task). So in order to correct it, you have to remove the value of the Epic link.

[WOLS]

I understand.

I'm not sure where I can remove the value.

I can't add an Epic-* field to the context fields. For Custom Fields, the Epic-* are displayed as LOCKED.