Hi Super6VCA,
SSO will stop working in following situations,
1. When the primary DC mentioned in the SSO Identity Source is decommissioned or down for some reason.
2. When vCenter server service isn't responding.
3. When the SSO Identity Source connectivity fails (this is related to first point above).
4. When there are certificate issue.
When all above goes out of control and cannot be fixed, only then I would go ahead with the application re-installation.
Thanks,