User is not added to groups when using delegated UD with external authenticator

Environment

• Delegated LDAP Directory
• Implement any SSO with external authenticator

Steps to Reproduce

• Ensure you have a Delegated LDAP with Sync on Login configured.
• Login with a user,
• Validate the user's ADS groups are sync'ed on login into Jira as Expected.
• Implement any SSO: - EXTEND CLASS: public final class Jira44CasAuthenticator extends JiraSeraphAuthenticator # IMPLEMENT ANY SSO. (Edit seraph-config.xml - it must point to your new Class).
• Add the user in another LDAP group AtlassianSuppliedConfluenceCode.txt
• Login with the user.
• The user DOES NOT become member of the external group in JIRA -

Expected Results

User should be added to the external groups when using SSO

Actual Results

Users groups are not updated

Notes

The same problem was happening in Confluence, it was addressed with a customised code as described in the issue: https://jira.atlassian.com/browse/CONFSERVER-24279
The code is attached to this issue