MQTT 消息发送给代理而不是客户端

Question

我有一个项目将 MQTT 消息从 ESP 发布到在 Pi 上运行的代理和在 Pi 上运行的客户端。消息从 ESP 可靠地发送到代理，因为我可以使用

mosquitto_sub

观察到它们，但是客户端只是偶尔收到它们。我尝试将 QOS 设置为 1 和 2，但仍未解决。想知道是否有人可以帮助我发现问题。

这里是 ESP（micropython）上的代码——这有效地工作得很好：

from umqtt.simple import MQTTClient

broker_ip = "[IP]"
client_name = "[client]"
user = "[user]"
password = "[password]"

def connect_publish(broker, client, topic, message, user, password):
    print("Creating client object...")
    client = MQTTClient(client_id=client_name,
                        server=broker_ip,
                        user=user,
                        password=password,
                        keepalive=60)
    print("Connecting to server...")
    client.connect()
    print("Publishing message")
    client.publish(topic = topic, msg = str(message), qos = 1)
    print("Published", message, "to", topic)
    print("Disconecting from server")
    client.disconnect()

[function to connect to wifi]
[initialize sensor]

while True:
    if [sensor_trigger]:
        connect_publish(broker = broker_ip,
                        client = client_name,
                        topic = b"sensor",
                        message = "on",
                        user = user,
                        password = password)

客户端代码 - 在 Pi (python) 上运行：

#!/usr/bin/env python3

import paho.mqtt.client as paho
import time

# The callback for when the client receives a CONNACK response from the server.
def on_connect(client, userdata, flags, rc):
    if rc == 0:
        print("Connected with result code " + str(rc))
    else: 
        print("Failed to subscribe, code:", rc)
    client.subscribe("sensor", qos = 1)

def on_message(client, userdata, msg):
    print(msg.topic+" "+ msg.payload.decode())
    if msg.payload.decode() == "on":
        if [some further conditions defined in variables below]:
            [do something]


#Initialize the variables for MQTT
BROKER = '[IP]'
#uname and password for mqtt client stored on pi: /etc/mosquitto/passwd
uname = '[user]'
pwd = '[password]'

#Initialize all the paho functions
client = paho.Client('[name]')
client.on_connect = on_connect
client.on_message = on_message
client.username_pw_set(password = pwd, username = uname)

client.connect(host = BROKER)
client.loop_start()

[initialize some more variables]

while True:
    [update some variables]
    time.sleep(0.1)

本质上，我在代理上可靠地看到了消息

mosquitto_sub

，但是在客户端上运行的

on_message

函数中没有看到打印语句（我也没有看到命令的结果）——即使使用了

qos = 1

。我试了 2 次，没什么区别。