Spec vs plan
If the spec and the plan live in the same ticket, every delivery change looks like a product change. They are different documents.
A spec answers what we are doing, for whom, and what done looks like. Problem, users, requirements, acceptance criteria, non-goals. It should survive a change of sprint without being rewritten.
A plan answers how we might ship it this time: approach, work packages, dependencies, risks. It can change when sequencing changes. That is not a spec failure.
Mixing them in Jira trains the team to treat every implementation note as a requirement. Draft the spec first. Send it to Plan only when the contract with the business is stable enough to brief delivery.
Working Draft keeps them as two tools on purpose. Paste the spec onward; do not merge the files.
Working Draft