A question about copied Job

there is a question when I copied a Job named ‘bbbb’ from an existed Job named ‘aaaa’,I find the Job BBBB misssing [Build] button. I want to know is this a bug either is this a special production design about Copied Job Business Logic ?

Legend:

bbbb

How did you copy the job? I get the build button.

Which Jenkins version are you using?

2.401.2
this is my test server :http://yanwenbo.net:8888/

open configuration and press save. Then the Build Button Should Appear