I believe you have have a misconfiguration with Traefik on your setup.
You’re running n8n with the flag N8N_PROTOCOL=HTTPS
This means that n8n will be encrypting the data between itself (n8n) and Traefik, who has to decrypt the data and re-encrypt it, which seems a possible cause for the issues you are having.
From the configuration alone I cannot tell the reason why it fails, but I would suggest you run traefik with n8n alone (no webhook or worker processes) just to make sure that the configuration between traefik and n8n is fine.