Upgrade 11.2.0.4 to 12.2.0.1 DBUA reporting There is no CRS resource associated with the database

I am trying to upgrade a RAC system from 11.2.0.4 to 12.2.0.1

We are using data guard and therefore have set db_unicque_name different on prod and DR site.

When running DBUA for upgrade it fails in checking phase

There is no CRS resource associated with the database

crs_stat shows

ora.exampel.db

db_unique_name on prod is exampel_prod and on DR exampel_dr

When runnig recommended command

srvctl modify database -db <db_unique_name> -dbname <db_name> as

srvctl modify database -db exampel_prod -dname exampel

it faisl with

PRCD-1120 : The resource for database exampel_prod could not be found.