Branch creation creating with old data after gitlab upgraded to 9.2.5

Hello Team,

      Recently we upgraded Gitlab-ce 8.14.6 to 9.2.5. After upgradation, developers tried to create new branch on top of one development branch. It is creating new branch with older code meaning with old commit id. not on latest code which they had (latest commit id on that branch).  If they tried to create new branch with particular commit id, it is creating properly.  Could you please let us know how to fix this issue. Why after upgradation, it is behaving like this?