I have a service sending messages to FCM using C# .NET8.
Starting from sunday evening no messages are sent and the following error is reported

Invalid value at ‘message.android.notification.event_time’ (type.googleapis.com/google.protobuf.Timestamp), Field ‘event_time’, Invalid time format: Failed to parse input

Problem is that event_time is not part of my message and never has been.
Messages are initialized like this:

            var message = new Message()
            {
               Notification = new Notification
               {
                  Title = title,
                  Body = bodyparts[0]
               },
               Android = new AndroidConfig()
               {
                  Priority = Priority.High,
                  Notification = new AndroidNotification()
                  {
                     Sound = "default",
                  },
               },
               Apns = new ApnsConfig()
               {
                  Aps = new Aps()
                  {
                     ContentAvailable = true,
                     Sound = "default",
                  },
               },
               Token = to
            };

I have tried to initialize notification like this

                  Notification = new AndroidNotification()
                  {
                     Sound = "default",
                     EventTimestamp = DateTime.UtcNow,
                  },

but errormessage is the same.

Can someone please help?
I have customers relying on the messageservice…

Regards Klaus