AppSheet API SSL Cert Expired?

[Stefan_QREW]

All AppSheet API Calls to one of our apps are failing with a 500 error

{ "type": "https://tools.ietf.org/html/rfc7231#section-6.6.1", "title": "An error occurred while processing your request.", "status": 500, "detail": "Error: Data table 'client' is not accessible due to: SSL Authentication Error.", "traceId": "00-23b5575fa5978c4880de15166e21d555-f737bd45d32d33db-00" }

Anybody else noticing this?