Runbook not visible in update action drop down of recovery plan after runbooks starting from alphabet 'S'

Question

I have created runbooks for a DR of an environment and have created a recovery plan for the same. Now when i try to attach the runbook in the steps of recovery plan, i am not able to find the runbooks after the names starting from S in the dropdown. I can see runbooks which were created later duration however not the ones with new ones. All runbooks , which are named after "S"alphabet is not visible in the drop down of recovery plan -update action section of pre/post-action.

Please note, all permissions are present, the names of the runbooks are fine as it is in published state.