[Ussuri] [horizon] Cannot Create Port with Fixed IP Address

Hi,

With Ussuri on Ubuntu 20.04, I can create port with fixed IP address by CLI but I cannot do the same by Horizon GUI. I find some error like following on /var/log/apache2/error.log

openstack_dashboard.dashboards.project.networks.ports.workflows Failed to create a port for network 91f04dfb-7f69-4050-8b3b-142ee555ae55: dictionary keys changed during iteration

By more inspection, I can find that horizon never send that create port request to neutron. So I think it is horizon problem. Is this expected result or is this horizon bug? Is this related to policy?

Best regards,