Hi,
I created a build plan and configured and enable automatic branch detection and automatic creation for remote links for JIRA issues to plan branch as following screen shot.

So I created Jira issue and then create branch by clicking "create branch " button on the right side menu.

Then it redirect to branch creation bitbucket page and I created branch with the name which contains Jira issue key.
After few moment, Bamboo successfully create plan branch and run build plan for newly created branch as I expected.
However, it does not automatically create remote link from Jira issue to plan branches but only create a link in bamboo with manual creation button as following screen shot.

So I searched if other people has similar issue and find out it was bug on previous version of bamboo and reported as resolved.
https://jira.atlassian.com/browse/BAM-13313
But I'm currently having similar issue and not sure how to resolve that.
Below is the current version information for applications we are using.
Bamboo: 6.1.1
JIRA: 7.3.6
Bitbucket: Cloud
Please let me know if there is a way to resolve it.
Thank you