When my Java-based server tries to send in-app push message to my App by calling FCM using https://fcm.googleapis.com/fcm/send URL, the following error is returned from FCM.
{
"succeeded":false,
"responseMessage":"Exception occurred; Hostname fcm.googleapis.com not verified:\n certificate: sha256/AVd9CvtM+BHfQgygNjExC4aOvHSEGRyX7Vvuus9jd9k=\n DN: CN=*.google.com\n subjectAltNames: [*.google.com, ...
It had been working well and this error started to occur suddenly a few days ago. In addition, the same FCM request is working well when using Postman. Is there anybody to help advise this erroneous situation?