SSLHandshakeException : timestamp check failed

I have a smart App I build to send metrics from ST into an InfluxDB database.
The smart app is using SSL and the destination have a valid SSL cert from Let’s Encrypt.

Everythng have been working for a year, and stopped working on the 20170120…

When I try the app I can see the error :

517f135b-9fdb-4e83-b6b5-11b5fd32871e 9:53:24 PM: error something went wrong: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path validation failed: java.security.cert.CertPathValidatorException: timestamp check failed

What have changed on the ST side ?