I have tested the Jira issues integration mentioned on a blog: https://blog.bitbucket.org/2018/09/03/jira-software-now-integrates-bitbucket-deployments/

Unfortunately, for all my deployments there is always shown{{Issues(0)}} even though the JIRA issues are mentioned in the commit message and when I click on Jira issue hyperlink in the commit message, the issue is open correctly.

There is a small error box in the left bottom corner but without any error details.