Failed to send, wrong host address or cannot reach address due to network issues

Hi,

we are using application insight agent 3.0.2 .
Created a custom availability test using application insight and powershell.
Ref: https://swimburger.net/blog/azure/run-availability-tests-using-powershell-and-azure-application-insights

It was working successfully for almost 1.5 years . since 31st March , data are not sent to azure on the scheduled interval (5m) .. Data are available once in an hour or two .

Below logs are found in the applicationinsight log file

ERROR c.m.a.i.c.c.TransmissionNetworkOutput - Failed to send, wrong host address or cannot reach address due to network issues
java.net.UnknownHostException: dc.services.visualstudio.com
at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
at java.net.InetAddress$2.lookupAllHostAddr(Unknown Source)
at java.net.InetAddress.getAddressesFromNameService(Unknown Source)
at java.net.InetAddress.getAllByName0(Unknown Source)
at java.net.InetAddress.getAllByName(Unknown Source)
at java.net.InetAddress.getAllByName(Unknown Source)
at org.apache.http.impl.conn.SystemDefaultDnsResolver.resolve(SystemDefaultDnsResolver.java:45)
at org.apache.http.impl.conn.DefaultHttpClientConnectionOperator.connect(DefaultHttpClientConnectionOperator.java:112)
at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.connect(PoolingHttpClientConnectionManager.java:359)
at org.apache.http.impl.execchain.MainClientExec.establishRoute(MainClientExec.java:381)
at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:237)
at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:185)
at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:89)
at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:111)
at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:185)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:83)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:108)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:56)
at com.microsoft.applicationinsights.internal.channel.common.ApacheSender43.sendPostRequest(ApacheSender43.java:79)
at com.microsoft.applicationinsights.internal.channel.common.TransmissionNetworkOutput.sendSync(TransmissionNetworkOutput.java:162)
at com.microsoft.applicationinsights.internal.channel.common.ActiveTransmissionNetworkOutput$1.run(ActiveTransmissionNetworkOutput.java:80)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
2023-04-25 12:11:38.606+03 ERROR c.m.a.i.c.c.TransmissionFileSystemOutput - Persistent storage max capacity has been reached; currently at 10486324 bytes. Telemetry will be lost, please consider increasing the value of MaxTransmissionStorageFilesCapacityInMB property in the configuration file.

what needs to be done to fix this issue ? Other than the availability tests , dependency and exception logs are not affected.