I tried below at 2:00 PM on 21/01/2025(JST).
Apple Push Notification service server certificate update
I followed above, a new server certificate: "SHA-2 Root : USERTrust RSA Certification Authority certificate" was added to my push server, but a certificate error occurred and push notifications could not be sent.
So I refered this article,Instead of connecting via DNS name resolution at api.development.push.apple.com, I fixed api.development.push.apple.com to "17.188.143.34" in /etc/hosts, I could push notifications with the new server certificate. (I got this IP(17.188.143.34) from this airtcle)
From this, I suspect that Apple had not yet updated the APNs certificate (CA) for the Sandbox environment as of 2:00 PM on January 21, 2025 (JST). Was the update published as scheduled?