Result returns the previous command (incorrect data)

[emil45]

Hello,
Running on production with paramiko (latest) for more than a year,
Recently the output returns somewhat messy, sometimes not full,
and, most of the time gets the output of the previous command.

I am not sure why,
will try to paste here the critical parts of the code (ifs, exceptions, etc. - removed for convince):

ssh_client = paramiko.SSHClient()
ssh_client.connect(..., 
                   allow_agent=False, 
                   look_for_keys=False, 
                   banner_timeout=60)
channel = ssh_client.invoke_shell(height=self._shell_height)

def send_command(cmd, patterns):
    while channel.recv_ready():
        channel.recv(1024)
        
    channel.sendall("%s\n" % cmd)
    
    buffer = ""
    
    while True:
        <timeout code here>
        
        data_read = channel.recv(1024)
        buffer += decode(data_read)
        for pattern in patterns:
            if re.search(pattern, buffer):
                return buffer

Is there a need for sleep somewhere in the code?