bonjour je reviens chez-vous car le problème persiste. 
j’ai eu l’idée de voir le log de mosquitto broker et voilà ce que j’ai :
1627293281: New connection from 172.30.32.1 on port 1883.
1627293281: Socket error on client <unknown>, disconnecting.
1627293401: New connection from 172.30.32.1 on port 1883.
1627293401: Socket error on client <unknown>, disconnecting.
1627293521: New connection from 172.30.32.1 on port 1883.
401: Unauthorized1627293522: Socket error on client <unknown>, disconnecting.
1627293642: New connection from 172.30.32.1 on port 1883.
1627293642: Socket error on client <unknown>, disconnecting.
1627293762: New connection from 172.30.32.1 on port 1883.
1627293762: Socket error on client <unknown>, disconnecting.
1627293882: New connection from 172.30.32.1 on port 1883.
401: Unauthorized1627293882: Socket error on client <unknown>, disconnecting.
1627294002: New connection from 172.30.32.1 on port 1883.
1627294002: Socket error on client <unknown>, disconnecting.
1627294122: New connection from 172.30.32.1 on port 1883.
1627294122: Socket error on client <unknown>, disconnecting.
1627294242: New connection from 172.30.32.1 on port 1883.
401: Unauthorized1627294243: Socket error on client <unknown>, disconnecting.
1627294363: New connection from 172.30.32.1 on port 1883.
1627294363: Socket error on client <unknown>, disconnecting.
c’est peut-être là le problème ?
sa configuration :
de plus faut-il un utilisateur pour mqtt ?
J’ai suivit tellement de façon de faire que je ne sais plus quoi penser.
Merci