On my Jenkins I configured:
Source Code Management
Git repository: https://bitbucket.org/username/project.git
credentials: username/
I'm doing the same but without the Bitbucket Plugin in my Jenkins.
I'm using the Jenkins Plugin in my Bitbucket. I've configured the webhook on each repository and pointing with the simply Jenkins URL. Then, into every job that I need, just leave checked the "Poll SCM" with/without schedule (is not required).
With that is working really well and I avoid another plugin installation in my Jenkins.