Additional IPs on vRack and Virtual Machines

Hi everyone !
Need help about Networking and VLAN as I can't ping the Gateway for Additional IP block from my VM nor reach the public IP from my laptop.

**Products:**
- 4 dedicated servers Advance-1 with each having 2 NICs for Proxmox cluster
- Additional IP, initially tied to one of the the DS (let's say DS-1), and actually the block is tied to the vRack.

**Goals:**
Here is the configuration I am trying to achieve :
- Create a hyperconverged proxmox cluster ( done )
- Deploy a Kubernetes cluster on the VMs managed by Proxmox ( not yet done )
- Having cilium (CNI) to manage a Load Balancer using one of my IP adress from the Additional IP block allowing my application to be be reachable from the Internet ( not yet done )
- Using ceph-csi (CSI) for k8s volumes

**Actual Configurations:**
Below is the description of my Proxmox cluster configuration:
- All of the Dedicated servers are tied into the vRack
- VLAN1 on the private NIC for Ceph cluster
- VLAN2 on the private NIC for Ceph public network and VM network via *vmbr20 bridge*
- Dedicated Servers Public NICs for VM migration and Proxmox cluster network
- Created a *bridge vmbr1* attached to some VMs acting as VM gateways to the Internet using public IP address from the Additional IP block (those VMs are also attached to vmbr20)

Actually ***everything is working*** great as expected!

But here is the issue, I can't use or don't known how to configure one of the Additional IP as a secondary IP of the VM NIC (let's say AdditionalIP-3 on nic0) that is attached to vmbr20 ( not using vmbr1 here )
I am not using vmbr1 here for testing purpose as my k8s nodes (VMs) will not use it and so do the VM that will be hosting the LB managed by cillium.

*Note that: AdditionalIP-1 and AdditionalIP-2 are already in use by the VMs acting as gateway*

Here is the configuration in the VM for the test:

allow-hotplug nic0
auto nic0
iface nic0 inet static
address 192.168.x.111
gateway 192.168.x.254

iface nic0 inet static
address AddionalIP-3
netmask AdditionalIP-Mask
broadcast AdditionalIP-BROADCAST
post-up ip route add AdditionalIP-Network/Mask dev nic0 table vrack
post-up ip route add default via AdditionalIP-GW dev nic0 table vrack
post-up ip rule add from AdditionalIP-Network/Mask table vrack
post-up ip rule add to AdditionalIP-Network/Mask table vrack

NIC configuration on the Host:

iface enPub inet manual
iface enPriv inet manual

#VLAN For VMs and Ceph public network
auto enPriv.2
iface enPriv.2 inet manual
auto vmbr20
iface vmbr20 inet static
address 192.168.x.xx/24
bridge-ports enPriv.2
bridge-stp off
bridge-fd

#VLAN For Ceph Cluster
auto enPriv.10
iface enPriv.10 inet static
address 192.168.y.yy/24

#IFACE for additional IP
auto vmbr1
iface vmbr1 inet manual
bridge-ports enPriv (just the DS NIC name without .vlanId )
bridge-stp off
bridge-fd 0

# Dedicated Servers NIC
auto vmbr0
iface vmbr0 inet static
address DS-Pub-IP/24
gateway DS-Pub-GW
bridge-ports enPub
bridge-stp off
bridge-fd 0
hwaddress NicMAC

**Test results:**
1. Ping on *AddionalIP-1* and *AddionalIP-2* from this VM having AddionalIP-3 **succeeds**.
2. Ping to *AddionalIP-GW* from the VM failed with: `From 192.168.x.111 icmp_seq=2 Destination Host Unreachable`
3. Ping or curl to AddionalIP-3 from external network (my laptop) failed ( no response )
4. traceroute from the VM to *AddionalIP-GW* show the following:

traceroute to AddionalIP-GW (AddionalIP-GW), 30 hops max, 60 byte packets
1 192.168.x.111 (192.168.x.111) 3066.148 ms !H 3066.133 ms !H 3066.125 ms !H

Here are my routing tables:

root@test:~# ip rule show table vrack
32764: from all to AdditionalIP-Network/Mask lookup vrack
32765: from AdditionalIP-Network/Mask lookup vrack

root@test:~# ip route show table vrack
default via AdditionalIP-GW dev nic0
AdditionalIP-Network/Mask dev nic0 scope link

root@test:~# ip route
default via VIP-VM-Gateway dev nic0 onlink
AdditionalIP-Network/Mask dev nic0 proto kernel scope link src AddionalIP-3
AdditionalIP-Network/Mask dev nic0 scope link src 192.168.x.111

**My Questions:**
Is it only possible to configure *nic0* (VM interface) that is attached to *vmbr20* (Proxmox) to have one additional IP configured on it next to the LAN IP (192.168.x.111) for it to be reachable from the Internet ? (Given that the LAN IP of this interface is tied to the VLAN2)
Or hopefully, Am I just missing something ?

Note:
- DS-1 is actually down

Many thanks in advance !!

*PS: I am far from being a network expert*

Edit:
- 1: ++More context and typo