Commits on Bitbucket account can be integrated with Issues under Issue tracker by adding #[issue_number]}}in the commit message. This functionality works fine if {{#[issue_number] doesn’t start the commit message, as shown below:

However, the functionality breaks when #[issue_number] starts the commit message and results in making the commit message a Header itself, shown below

Workaround:
Disable the beta feature “Commit list as a single page app” under the Bitbucket settings > Labs

Also affect any # in the commit