Wrong build is shown after PR is merged

• Have a pipeline setup for a project. It should trigger on each commit.
• Create a PR. Open it. (Optionally tick "Close branch after merge").
• Click "Merge".
  Expected: The icon on the top right (see screenshot) is showing "Build in progress" icon. It should show merge commit build status.
  Actual: It shows last commit build status for a branch which no longer exists.

GitHub is smart here. It shows merge commit build status.
Bitbucket shows irrelevant data.

Since Pipelines implemented the "Deployments" feature I believe this is a critical bug to fix. We need to know if this PR is responsible for a build failure, or the software was released fine.