Unexpected exception while processing MQTT message

Hi I am getting the below error in greengrass.log (in core) each time I run the basic_discovery.py from a client device. The messages arrive and I can check them in MQTT tester but I need to see when

2023-12-20T21:14:50.501Z [ERROR] (nioEventLoopGroup-3-2) io.moquette.broker.NewNettyMQTTHandler: Unexpected exception while processing MQTT message. Closing Netty channel. CId=private_laptop. {}
java.io.IOException: Connection reset by peer
        at java.base/sun.nio.ch.FileDispatcherImpl.read0(Native Method)
        at java.base/sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:39)
        at java.base/sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:276)
        at java.base/sun.nio.ch.IOUtil.read(IOUtil.java:233)
        at java.base/sun.nio.ch.IOUtil.read(IOUtil.java:223)
        at java.base/sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:356)
        at io.netty.buffer.PooledByteBuf.setBytes(PooledByteBuf.java:256)
        at io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:1132)
        at io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:357)
        at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:151)
        at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:788)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:724)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:650)
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562)
        at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
        at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
        at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
        at java.base/java.lang.Thread.run(Thread.java:829)

Here are all my versions and environment setup: GG version: 2.12.1 Nucleus: 2.12.1 aws.greengrass.clientdevices.Auth 2.4.5 and configured as follows:

{
	"deviceGroups": {
		"formatVersion": "2021-03-05",
		"definitions": {
			"MyDeviceGroup": {
				"selectionRule": "thingName: private_laptop",
				"policyName": "MyClientDevicePolicy"
			}
		},
		"policies": {
			"MyClientDevicePolicy": {
				"AllowConnect": {
					"statementDescription": "Allow client devices to connect.",
					"operations": [
						"mqtt:connect"
					],
					"resources": [
						"*"
					]
				},
				"AllowPublish": {
					"statementDescription": "Allow client devices to publish to all topics.",
					"operations": [
						"mqtt:publish"
					],
					"resources": [
						"*"
					]
				},
				"AllowSubscribe": {
					"statementDescription": "Allow client devices to subscribe to all topics.",
					"operations": [
						"mqtt:subscribe"
					],
					"resources": [
						"*"
					]
				}
			}
		}
	}
}

MQTT 3.1.1 broker is used with default config MQTT bridge is configured as follows:

{
	"mqttTopicMapping": {
		"HelloWorldIotCoreMapping": {
			"topic": "clients/+/hello/world",
			"source": "LocalMqtt",
			"target": "IotCore"
		}
	}
}

• IP detector is used with default config.
• Client device is associated with the core device
• Both client and core are added to the same thing group - Thing group has a policy to allow all iot* and greengrass::* for all resources (GreengrassV2IoTThingPolicy)
• The core device is a Raspberry pi 3 B+ and the client device is Windows laptop
• Core has a lot of free memory
• 8883 port is opened on the core Any idea what can be the reason for this error?