Pull request created through Jira selects the wrong source branch

When creating a pull request from a Jira ticket, the branch associated with the ticket is not selected as the source branch by default. Instead, the last used branch is selected.

Steps to reproduce:

• Create a branch on Bitbucket related to a Jira ticket (i.e. hotfix/ABC-32-newfix)
• On Jira, create a pull request through the ticket associated with the branch (ABC-32)

Expected outcome:

• Bitbucket Pull request being auto populated with the branch hotfix/ABC-32-newfix as the source branch

Actual outcome:

• Bitbucket Pull request selects the last used as the source branch.