Incomplete binary messages received in Python STOMP client

I am trying to exchange binary messages between two Python STOMP clients.

Message sending and receiving have no issues. However, there are always a few bytes (seems random) missing on the receiver.

The same messages are received in whole by C++ clients. No issue either when ASCII text are sent.

What am I missing?

• Python: 3.10
• Stomp: 7.0.0
• ActiveMQ: 5.16.3

Publisher:

import random
import string
import time 
import sys
import stomp
import os

hosts = [('localhost', 61613)]
conn = stomp.Connection(host_and_ports=hosts)
conn.connect('admin', 'admin', wait=True)
while 1:
    b = bytes(os.urandom(100))
    #b = ''.join(random.choices(string.ascii_lowercase, k=1500))
    print(len(b))
    conn.send(content_lengh=len(b), body=b, destination='/queue/test')
    time.sleep(2)
    
conn.disconnect()

Subscriber:

import time
import sys
import stomp

class MyListener(stomp.ConnectionListener):
    def on_error(self, frame):
        print('received an error "%s"' % frame.body)

    def on_message(self, frame):
        print(type(frame.body))
        print('received message len = "%s"' % len(frame.body))

conn = stomp.Connection()
conn.set_listener('', MyListener())
conn.connect('admin', 'password', wait=True)
conn.subscribe(destination='/queue/test', id=1, ack='auto')

print("Waiting for messages...")
while 1: 
  time.sleep(10)
conn.disconnect()

I figured it out myself by tracing STOMP. The subscriber needs to disable auto decode as shown below. Otherwise, the frame body will be decoded as UTF-8.

conn = stomp.Connection(auto_decode=False)