diff --git a/spring-cloud-function-adapters/spring-cloud-function-adapter-gcp/src/test/java/org/springframework/cloud/function/adapter/gcp/integration/LocalServerTestSupport.java b/spring-cloud-function-adapters/spring-cloud-function-adapter-gcp/src/test/java/org/springframework/cloud/function/adapter/gcp/integration/LocalServerTestSupport.java
index 246a886df..ea5bd3acd 100644
--- a/spring-cloud-function-adapters/spring-cloud-function-adapter-gcp/src/test/java/org/springframework/cloud/function/adapter/gcp/integration/LocalServerTestSupport.java
+++ b/spring-cloud-function-adapters/spring-cloud-function-adapter-gcp/src/test/java/org/springframework/cloud/function/adapter/gcp/integration/LocalServerTestSupport.java
@@ -59,7 +59,7 @@ final public class LocalServerTestSupport {
 
 	private static final String SERVER_READY_STRING = "Started ServerConnector";
 
-	private static AtomicInteger nextPort = new AtomicInteger(8080);
+	private static AtomicInteger nextPort = new AtomicInteger(55555);
 
 	private LocalServerTestSupport() {
 	}
diff --git a/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/catalog/SimpleFunctionRegistry.java b/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/catalog/SimpleFunctionRegistry.java
index af9b64969..fe278d55a 100644
--- a/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/catalog/SimpleFunctionRegistry.java
+++ b/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/catalog/SimpleFunctionRegistry.java
@@ -687,7 +687,7 @@ public class SimpleFunctionRegistry implements FunctionRegistry, FunctionInspect
 				// Set the contentType header to the value of accept for "legacy" reasons. But, do not set the
 				// contentType header to the value of accept if it is a wildcard type, as this doesn't make sense.
 				// This also applies to the else branch below.
-				if (acceptedContentType.isConcrete()) {
+				if (acceptedContentType.isConcrete() && !headersMap.containsKey(MessageHeaders.CONTENT_TYPE)) {
 					headersMap.put(MessageHeaders.CONTENT_TYPE, acceptedContentType);
 				}
 			}
diff --git a/spring-cloud-function-samples/function-sample-aws-custom/pom.xml b/spring-cloud-function-samples/function-sample-aws-custom/pom.xml
index 85e6325ba..a25700aeb 100644
--- a/spring-cloud-function-samples/function-sample-aws-custom/pom.xml
+++ b/spring-cloud-function-samples/function-sample-aws-custom/pom.xml
@@ -33,14 +33,6 @@
 					<groupId>org.springframework.boot</groupId>
 					<artifactId>spring-boot-starter-json</artifactId>
 				</exclusion>
-				<exclusion>
-					<groupId>io.netty</groupId>
-					<artifactId>netty-codec-http2</artifactId>
-				</exclusion>
-				<exclusion>
-					<groupId>io.netty</groupId>
-					<artifactId>netty-transport-native-epoll</artifactId>
-				</exclusion>
 				<exclusion>
 					<groupId>org.hibernate.validator</groupId>
 					<artifactId>hibernate-validator</artifactId>
diff --git a/spring-cloud-function-samples/function-sample-gcp-background/pom.xml b/spring-cloud-function-samples/function-sample-gcp-background/pom.xml
index 55a03c849..ef0f51c94 100644
--- a/spring-cloud-function-samples/function-sample-gcp-background/pom.xml
+++ b/spring-cloud-function-samples/function-sample-gcp-background/pom.xml
@@ -66,4 +66,33 @@
 			</plugin>
 		</plugins>
 	</build>
+	<repositories>
+		<repository>
+			<id>spring-snapshots</id>
+			<name>Spring Snapshots</name>
+			<url>https://repo.spring.io/libs-snapshot-local</url>
+			<snapshots>
+				<enabled>true</enabled>
+			</snapshots>
+			<releases>
+				<enabled>false</enabled>
+			</releases>
+		</repository>
+		<repository>
+			<id>spring-milestones</id>
+			<name>Spring Milestones</name>
+			<url>https://repo.spring.io/libs-milestone-local</url>
+			<snapshots>
+				<enabled>false</enabled>
+			</snapshots>
+		</repository>
+		<repository>
+			<id>spring-releases</id>
+			<name>Spring Releases</name>
+			<url>https://repo.spring.io/release</url>
+			<snapshots>
+				<enabled>false</enabled>
+			</snapshots>
+		</repository>
+	</repositories>
 </project>
diff --git a/spring-cloud-function-samples/function-sample-supplier-exporter/pom.xml b/spring-cloud-function-samples/function-sample-supplier-exporter/pom.xml
index b2f412e12..67b7b2574 100644
--- a/spring-cloud-function-samples/function-sample-supplier-exporter/pom.xml
+++ b/spring-cloud-function-samples/function-sample-supplier-exporter/pom.xml
@@ -28,16 +28,6 @@
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-webflux</artifactId>
-			<exclusions>
-				<exclusion>
-					<groupId>io.netty</groupId>
-					<artifactId>netty-transport-native-epoll</artifactId>
-				</exclusion>
-				<exclusion>
-					<groupId>io.netty</groupId>
-					<artifactId>netty-codec-http2</artifactId>
-				</exclusion>
-			</exclusions>
 		</dependency>
 		<dependency>
 			<groupId>org.springframework.cloud</groupId>
diff --git a/spring-cloud-function-samples/pom.xml b/spring-cloud-function-samples/pom.xml
index c98da4cb2..cd6903ddd 100644
--- a/spring-cloud-function-samples/pom.xml
+++ b/spring-cloud-function-samples/pom.xml
@@ -26,7 +26,7 @@
 		<module>function-sample-azure</module>
 		<!--><module>function-sample-spring-integration</module>-->
 		<module>function-sample-gcp-http</module>
-		<module>function-sample-gcp-background</module>
+<!-- 		<module>function-sample-gcp-background</module> -->
 	</modules>
 
 	<build>