diff --git a/tests/cts/net/src/android/net/cts/ConnectivityDiagnosticsManagerTest.java b/tests/cts/net/src/android/net/cts/ConnectivityDiagnosticsManagerTest.java
index a40c92d852..721ad82ff5 100644
--- a/tests/cts/net/src/android/net/cts/ConnectivityDiagnosticsManagerTest.java
+++ b/tests/cts/net/src/android/net/cts/ConnectivityDiagnosticsManagerTest.java
@@ -73,6 +73,7 @@ import android.platform.test.annotations.AppModeFull;
 import android.telephony.CarrierConfigManager;
 import android.telephony.SubscriptionManager;
 import android.telephony.TelephonyManager;
+import android.util.ArraySet;
 import android.util.Pair;
 
 import androidx.test.InstrumentationRegistry;
@@ -92,7 +93,9 @@ import org.junit.runner.RunWith;
 
 import java.security.MessageDigest;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
+import java.util.Set;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.Executor;
 import java.util.concurrent.TimeUnit;
@@ -293,7 +296,7 @@ public class ConnectivityDiagnosticsManagerTest {
 
         final String interfaceName =
                 mConnectivityManager.getLinkProperties(network).getInterfaceName();
-        connDiagsCallback.expectOnConnectivityReportAvailable(
+        connDiagsCallback.maybeVerifyConnectivityReportAvailable(
                 network, interfaceName, TRANSPORT_CELLULAR, NETWORK_VALIDATION_RESULT_VALID);
         connDiagsCallback.assertNoCallback();
     }
@@ -426,10 +429,15 @@ public class ConnectivityDiagnosticsManagerTest {
         cb.expectOnNetworkConnectivityReported(mTestNetwork, hasConnectivity);
 
         // All calls to #onNetworkConnectivityReported are expected to be accompanied by a call to
-        // #onConnectivityReportAvailable for S+ (for R, ConnectivityReports were only sent when the
-        // Network was re-validated - when reported connectivity != known connectivity).
-        if (SdkLevel.isAtLeastS() || !hasConnectivity) {
+        // #onConnectivityReportAvailable for T+ (for R, ConnectivityReports were only sent when the
+        // Network was re-validated - when reported connectivity != known connectivity). On S,
+        // recent module versions will have the callback, but not the earliest ones.
+        if (!hasConnectivity) {
             cb.expectOnConnectivityReportAvailable(mTestNetwork, interfaceName);
+        } else if (SdkLevel.isAtLeastS()) {
+            cb.maybeVerifyConnectivityReportAvailable(mTestNetwork, interfaceName, TRANSPORT_TEST,
+                    getPossibleDiagnosticsValidationResults(),
+                    SdkLevel.isAtLeastT() /* requireCallbackFired */);
         }
 
         cb.assertNoCallback();
@@ -485,18 +493,25 @@ public class ConnectivityDiagnosticsManagerTest {
             // Test Networks both do not require validation and are not tested for validation. This
             // results in the validation result being reported as SKIPPED for S+ (for R, the
             // platform marked these Networks as VALID).
-            final int expectedNetworkValidationResult =
-                    SdkLevel.isAtLeastS()
-                            ? NETWORK_VALIDATION_RESULT_SKIPPED
-                            : NETWORK_VALIDATION_RESULT_VALID;
-            expectOnConnectivityReportAvailable(
-                    network, interfaceName, TRANSPORT_TEST, expectedNetworkValidationResult);
+
+            maybeVerifyConnectivityReportAvailable(network, interfaceName, TRANSPORT_TEST,
+                    getPossibleDiagnosticsValidationResults(), true);
         }
 
-        public void expectOnConnectivityReportAvailable(@NonNull Network network,
+        public void maybeVerifyConnectivityReportAvailable(@NonNull Network network,
                 @NonNull String interfaceName, int transportType, int expectedValidationResult) {
+            maybeVerifyConnectivityReportAvailable(network, interfaceName, transportType,
+                    new ArraySet<>(Collections.singletonList(expectedValidationResult)), true);
+        }
+
+        public void maybeVerifyConnectivityReportAvailable(@NonNull Network network,
+                @NonNull String interfaceName, int transportType,
+                Set<Integer> possibleValidationResults, boolean requireCallbackFired) {
             final ConnectivityReport result =
                     (ConnectivityReport) mHistory.poll(CALLBACK_TIMEOUT_MILLIS, x -> true);
+            if (!requireCallbackFired && result == null) {
+                return;
+            }
             assertEquals(network, result.getNetwork());
 
             final NetworkCapabilities nc = result.getNetworkCapabilities();
@@ -508,8 +523,8 @@ public class ConnectivityDiagnosticsManagerTest {
             final PersistableBundle extras = result.getAdditionalInfo();
             assertTrue(extras.containsKey(KEY_NETWORK_VALIDATION_RESULT));
             final int actualValidationResult = extras.getInt(KEY_NETWORK_VALIDATION_RESULT);
-            assertEquals("Network validation result is incorrect",
-                    expectedValidationResult, actualValidationResult);
+            assertTrue("Network validation result is incorrect: " + actualValidationResult,
+                    possibleValidationResults.contains(actualValidationResult));
 
             assertTrue(extras.containsKey(KEY_NETWORK_PROBES_SUCCEEDED_BITMASK));
             final int probesSucceeded = extras.getInt(KEY_NETWORK_VALIDATION_RESULT);
@@ -556,6 +571,19 @@ public class ConnectivityDiagnosticsManagerTest {
         }
     }
 
+    private static Set<Integer> getPossibleDiagnosticsValidationResults() {
+        final Set<Integer> possibleValidationResults = new ArraySet<>();
+        possibleValidationResults.add(NETWORK_VALIDATION_RESULT_SKIPPED);
+
+        // In S, some early module versions will return NETWORK_VALIDATION_RESULT_VALID.
+        // Starting from T, all module versions should only return SKIPPED. For platform < T,
+        // accept both values.
+        if (!SdkLevel.isAtLeastT()) {
+            possibleValidationResults.add(NETWORK_VALIDATION_RESULT_VALID);
+        }
+        return possibleValidationResults;
+    }
+
     private class CarrierConfigReceiver extends BroadcastReceiver {
         // CountDownLatch used to wait for this BroadcastReceiver to be notified of a CarrierConfig
         // change. This latch will be counted down if a broadcast indicates this package has carrier