Then Copyartifact plugin injected the environment variable COPYARTIFACT_BUILD_NUMBER<"from" project name> as BUILD_DISPLAY_NAME without the "#", instead of the BUILD_NAME.
In the following example,
The "from" project environment variables (called "ERGON_HADES_NG_X_GERARPACOTEXML")
BUILD_DISPLAY_NAME #161
BUILD_ID 149
BUILD_NUMBER 149

The project using the copyartifact plugin
COPYARTIFACT_BUILD_NUMBER_ERGON_HADES_NG_X_GERARPACOTEXML=161