So this project was recently created on Jira, where resolution field was missing. Since we are using Company Managed Jira, I requested to add resolution field to all the issue types.
Once the resolution field was added, what I see is when new issues are created, by default issues are with resolution set to unresolved, due to which there is no strike-through over Jira issues when I see in Backlog, but suppose I want to edit the issue, let's say add few more details like adding Sprint, Epic Link, Updating Story Points, then automatically in the edit pop up, resolution shows complete as status, which we have to manually set it back to incomplete. Also due to this, there is strike-through over the issues.
What can I do to resolve this ? Only issues with resolution as unresolved are not strike-through stories, and there is no option to select unresolved, while editing the issue.