[Octavia dashboard] Impossible to fill the subnet field when creating a load balancer

Hi All, On my OSA Victoria deployment (on Ubuntu 20.04), the "Create Load Balancer" form does not allow me to fill the mandatory "subnet" field and therefore I can't create a load balancer with Horizon. On the other hand, Octavia works fine and I can create load balancers with the CLI, Terraform, etc. Has one of you already faced such a situation ? Best regards, Jean-François