Why does salt-syndic throw a TransportWarning about an unclosed transport on startup?

Question

I'm experiencing an issue with salt-syndic on my system running Red Hat Enterprise Linux Server release 7.9 (Maipo) with SaltStack version 3006.5 (Sulfur). When I attempt to start the salt-syndic service, I encounter a TransportWarning related to an unclosed transport. The detailed error message is as follows:

/opt/saltstack/salt/bin/python3.10 /usr/bin/salt-syndic MainProces
/opt/saltstack/salt/lib/python3.10/site-packages/salt/transport/base.py:129: TransportWarning: Unclosed transport! <salt.transport.zeromq.RequestClient object at 0x7f6c08e39450> 
  File "/usr/bin/salt-syndic", line 11, in <module>
    sys.exit(salt_syndic())

  File "/opt/saltstack/salt/lib/python3.10/site-packages/salt/scripts.py", line 401, in salt_syndic
    syndic.start()

  File "/opt/saltstack/salt/lib/python3.10/site-packages/salt/cli/daemons.py", line 601, in start
    self.syndic.tune_in()

  File "/opt/saltstack/salt/lib/python3.10/site-packages/salt/minion.py", line 3742, in tune_in
    self.io_loop.start()

  File "/opt/saltstack/salt/lib/python3.10/site-packages/salt/ext/tornado/ioloop.py", line 834, in start
    self._run_callback(self._callbacks.popleft())

  File "/opt/saltstack/salt/lib/python3.10/site-packages/salt/ext/tornado/ioloop.py", line 606, in _run_callback
    ret = callback()

  File "/opt/saltstack/salt/lib/python3.10/site-packages/salt/ext/tornado/stack_context.py", line 278, in null_wrapper
    return fn(*args, **kwargs)

  File "/opt/saltstack/salt/lib/python3.10/site-packages/salt/ext/tornado/gen.py", line 1153, in inner
    self.run()

  File "/opt/saltstack/salt/lib/python3.10/site-packages/salt/ext/tornado/gen.py", line 1070, in run
    yielded = self.gen.send(value)

  File "/opt/saltstack/salt/lib/python3.10/site-packages/salt/minion.py", line 1405, in connect_master
    self.req_channel = salt.channel.client.AsyncReqChannel.factory(

  File "/opt/saltstack/salt/lib/python3.10/site-packages/salt/channel/client.py", line 137, in factory
    transport = salt.transport.request_client(opts, io_loop=io_loop)

  File "/opt/saltstack/salt/lib/python3.10/site-packages/salt/transport/base.py", line 47, in request_client
    return salt.transport.zeromq.RequestClient(opts, io_loop=io_loop)

  File "/opt/saltstack/salt/lib/python3.10/site-packages/salt/transport/zeromq.py", line 890, in __init__
    super().__init__(opts, io_loop)

  File "/opt/saltstack/salt/lib/python3.10/site-packages/salt/transport/base.py", line 145, in __init__
    super().__init__()

  warnings.warn(
TransportWarning: Enable tracemalloc to get the object allocation traceback

This warning appears during the startup process of salt-syndic and seems to be related to the ZeroMQ transport layer.

Here are the details of my setup:

• Operating System: Red Hat Enterprise Linux Server release 7.9 (Maipo)
• SaltStack Version: 3006.5 (Sulfur)

Can anyone help me understand why this warning is occurring and how to resolve it? Is this a known issue with this version of SaltStack, or could it be related to my specific setup?

Any insights or suggestions would be greatly appreciated.

I don't know what went wrong, and I can't find any relevant information online.