Empty required fields are not validated by Atlassian when creating Jira tickets programmatically through Jira APIs

We have developed a Jira Datacenter plugin that programmatically creates Jira tickets. We are using Jira-core 8.6.0 and invoking the “createIssueObject(ApplicationUser var1, Issue var2)” method in the “IssueManager” interface for ticket creation.
However, when we configure custom fields as required in the Jira UI and attempt to create tickets through our plugin with empty values, the tickets are being created successfully, even though there are empty required fields. In this situation, it is expected that Atlassian should block the issue creation due to the presence of empty required fields.
We have also tested this scenario using Jira-core 9.4.7 version, but the issue persists.
Could you kindly provide a solution for this issue? For troubleshooting purposes, I have attached a test Jira plugin along with its code base.
plugin Codebase: Jira-test-plugin
Test Plugin: Jira-Plugin