diff --git a/driver-sync/src/test/functional/com/mongodb/client/AbstractClientSideEncryptionExplicitEncryptionTest.java b/driver-sync/src/test/functional/com/mongodb/client/AbstractClientSideEncryptionExplicitEncryptionTest.java
index 9f4594143f1..45e7e26fb9d 100644
--- a/driver-sync/src/test/functional/com/mongodb/client/AbstractClientSideEncryptionExplicitEncryptionTest.java
+++ b/driver-sync/src/test/functional/com/mongodb/client/AbstractClientSideEncryptionExplicitEncryptionTest.java
@@ -43,6 +43,7 @@
 
 import static com.mongodb.ClusterFixture.isStandalone;
 import static com.mongodb.ClusterFixture.serverVersionAtLeast;
+import static com.mongodb.ClusterFixture.serverVersionLessThan;
 import static com.mongodb.client.Fixture.getDefaultDatabase;
 import static com.mongodb.client.Fixture.getDefaultDatabaseName;
 import static com.mongodb.client.Fixture.getMongoClient;
@@ -138,6 +139,10 @@ public void canInsertEncryptedIndexedAndFind() {
 
     @Test
     public void canInsertEncryptedIndexedAndFindWithNonZeroContention() {
+        // JAVA-6237: this test inserts with contentionFactor 10 but encryptedFields.json configures the
+        // encryptedIndexed field with contention 0. Servers >= 9.0 reject this mismatch (SERVER-91887);
+        // skip until the spec prose test is corrected (DRIVERS-3547).
+        assumeTrue(serverVersionLessThan(9, 0));
         EncryptOptions encryptOptions = new EncryptOptions("Indexed").keyId(key1Id).contentionFactor(10L);
         MongoCollection<BsonDocument> coll = encryptedClient.getDatabase(getDefaultDatabaseName())
                 .getCollection("explicit_encryption", BsonDocument.class);
diff --git a/driver-sync/src/test/functional/com/mongodb/client/unified/UnifiedTestModifications.java b/driver-sync/src/test/functional/com/mongodb/client/unified/UnifiedTestModifications.java
index 286e6f525a5..7b432acd050 100644
--- a/driver-sync/src/test/functional/com/mongodb/client/unified/UnifiedTestModifications.java
+++ b/driver-sync/src/test/functional/com/mongodb/client/unified/UnifiedTestModifications.java
@@ -63,8 +63,18 @@ public static void applyCustomizations(final TestDef def) {
         // Client side encryption (QE)
         def.skipJira("https://jira.mongodb.org/browse/JAVA-5675 Support QE with Client.bulkWrite")
                 .file("client-side-encryption/tests/unified", "client bulkWrite with queryable encryption");
+        def.skipJira("https://jira.mongodb.org/browse/JAVA-6244 QE GA \"substring\" query type is not yet "
+                        + "implemented (DRIVERS-3540)")
+                .file("client-side-encryption/tests/unified", "QE-Text-substring");
 
         // client-side-operation-timeout (CSOT)
+        // The expected change stream timeout-refresh behaviour is unspecified on server 9.0+ (DRIVERS-3006), so the
+        // CSOT suite fails there (most visibly on sharded clusters, where extra mongos round-trips exceed the tight
+        // timeoutMS). Skip the suite on 9.0+ until the spec is clarified.
+        def.skipJira("https://jira.mongodb.org/browse/JAVA-6078 change stream timeout-refresh behaviour is "
+                        + "unspecified on server 9.0+ (DRIVERS-3006)")
+                .when(() -> !serverVersionLessThan(9, 0))
+                .directory("client-side-operations-timeout");
         def.retry("Unified CSOT tests do not account for RTT which varies in TLS vs non-TLS runs")
                 .whenFailureContains("timeout")
                 .test("client-side-operations-timeout",
@@ -473,6 +483,14 @@ public static void applyCustomizations(final TestDef def) {
                 .file("transactions", "backpressure-retryable-commit");
         def.skipJira("https://jira.mongodb.org/browse/JAVA-5956 TODO-JAVA-5956")
                 .file("transactions", "backpressure-retryable-abort");
+        def.skipJira("https://jira.mongodb.org/browse/JAVA-6179")
+                .test("transactions", "retryable-writes", "increment txnNumber")
+                .test("transactions", "commit", "reset session state commit")
+                .test("transactions", "commit", "reset session state abort")
+                .test("transactions-convenient-api", "callback-commits",
+                        "withTransaction still succeeds if callback commits and runs extra op")
+                .test("transactions-convenient-api", "callback-aborts",
+                        "withTransaction still succeeds if callback aborts and runs extra op");
 
         // valid-pass
 
diff --git a/testing/resources/specifications b/testing/resources/specifications
index 44840386103..d4d0cdf2645 160000
--- a/testing/resources/specifications
+++ b/testing/resources/specifications
@@ -1 +1 @@
-Subproject commit 44840386103b93e5ebb7d7d595ca605c44eb6e08
+Subproject commit d4d0cdf264513676b1c12c3fcb899dd1e4b789b6