Openstack / Linux Networking - public network doesnt connect with physical interface

I'm currently setting up Openstack with kolla-ansible wallaby, version 12.3.1.dev95, all-in-one installation. \

My setup in VMWare:
Workstation 14.x
VM-OS: Ubuntu Server20.04 LTS
1 Bridge-Mode network interface
2 private Host-only networks (1 with DHCP network 203.1.2.0/25; range 203.1.2.1-203.1.2.126).
All networks are attached to the openstack-VM (ens33, ens34 and ens35).
ens34: 203.1.2.4/24
ens35: no IP assigned

The configuration for the globals.yml:
kolla_base_distro: "ubuntu"
kolla_install_type: "source"
network_interface: ens34
neutron_external_interface: ens35
kolla_internal_vip_address: "203.1.2.4"
enable_haproxy: "no"
nova_console: "spice"

My Problem:
After setting up a public network with the following command

openstack network create --external --provider-physical-network physnet1 \
--provider-network-type flat public

and a subnet

openstack subnet create --no-dhcp \
--allocation-pool start=203.1.2.150,end=203.1.2.199 --network public \
--subnet-range 203.1.2.128/25 public-subnet

The public network is connected to a router (203.1.2.176) which should be pingable but isn't. Because the standard rules should allow that (from my point of view).

EDIT: I looked a little bit deeper and found that i could ping anything from the openstack network namespace. How do I connect my second physical interface with the namespace, in a way that this interface represents my public network?

Example: I have network namespace A with veth A1. A1 has all networking attached to it (floating ips, router, etc.). Now, what i want to do is that my second physical interface has these information attached to it.

If you need more information, I'm happy to provide it :)

PS: I hope this is somehow an acceptable description of my problem ^^'