A place to start troubleshooting is to see if your Test Plan is in a Closed state. In the closed state, the item is immutable and extends to Xray where it blocks new TEs from being created within the Test Plan by selecting tests and clicking “Create Test Execution” in the Jira widget. If this is the root cause, moving the Test plan to in progress and then adding the test execution should resolve the issue.

A current workaround to alleviate this issue is to update the Ketryx default workflow scheme. Set the scheme such that Xray Test Plan issues do not have a Resolved state, are transitioned to Closed by the user and not by approvals, and does not have an immutable Closed state. This is acceptable because within Ketryx the Test plan needs to be approved before the release can be made, so there is still control over approving the Xray test plan.