Raspberry Pi Pico W - umqtt clean_session=False -[Errno 12] ENOMEM

Hello,
I'm using a raspberry pi pico w to connect to a mqtt server. The clean sesssion connection works pretty well but when I try to use client.connect(False) it returns the error: OSError: [Errno 12] ENOMEM

Here a snippet of the code:

`
from umqtt.robust import MQTTClient
def mqtt_connect():

client = MQTTClient(client_id, mqtt_server, port, username, pwd,  keepalive=3600)
client.set_callback(on_message)
client.on_message = on_message
while (client.connect(False) != 0):
    print('Waiting for MQTT connection...')
    sleep(1)
print('Connected to %s MQTT Broker'%(mqtt_server))
client.subscribe(topic_sub)
print("Connected to %s, subscribed to %s topic" % (mqtt_server, topic_sub))

return client

`
and the Error:

Waiting for MQTT connection...
Waiting for MQTT connection...
Waiting for MQTT connection...
Waiting for MQTT connection...
Waiting for MQTT connection...
Traceback (most recent call last):
File "", line 189, in
File "", line 71, in mqtt_connect
File "/lib/umqtt/simple.py", line 66, in connect
OSError: [Errno 12] ENOMEM

Can you help me please?

Thanks

Reproduce the reported connection path on a Raspberry Pi Pico W using the provided mqtt_connect snippet, comparing client.connect(False) with the working clean-session connection. Then inspect /lib/umqtt/simple.py at connect, especially the path reached by connect(False); done means identifying the ENOMEM cause and documenting or fixing the behavior.