Membership Status not updating beyond Grace to Expired
It sounds like there's a misconfiguration of your Membership Status Rules.
Please review them at Administer menu &gt;&gt; CiviMember &gt;&gt; Membership Status Rules.  Pay special attention to the Grace and Expired rules, especially to the Start Date Adjustment and End Date Adjustment.
If you're not sure how to interpret what you're seeing, feel free to edit your question to include screenshots.