Pushing new branch triggers comments to issues

From a support issue:

I'm having a problem and I 'm not sure if it is a bug or if it is pilot error.

I recently started marking issues 'resolved' by including "Fixed #x" in my commit messages. This marks the issue resolved as expected.

However, now any time I push a new branch to bitbucket each issue that was 'auto-marked' previously is auto marked again.
Here is the workflow that reproduces this problem:

To summarize:

1. Create local branch X
2. Push branch X to origin
3. Alter branch X locally
4. Commit branch X locally with message that includes "Fixed BCLOUD-1" to mark issue 1 resolved.
5. Push branch X to origin *** At this point, issue BCLOUD-1 is automatically marked resolved.
6. Create and accept pull request to merge branch X with master
7. Locally, checkout master and pull from origin
8. Create new branch Y.
9. Push branch Y to origin *** At this point, issue BCLOUD-1 is commented on again automatically
   It seems like the "Fixed BCLOUD-1" message is persisting somehow and each time I push a branch, it triggers another round of issue comments and emails. I'm using Git if that matters.