Proxmox-VE 6 / PFSense, Problems with the iptables - iptables

Question

I have been trying for some time to configure my Proxmox with a PFSense VM filtering internet traffic to my other VMs.
So far I have managed to install PFSense and configure the Proxmox interfaces. I have also managed to go to the PFSense web interface. However, my VMs do not always have access to the internet, so I try to modify my iptables to manage to redirect all the traffic on PFSense.
Here are my interfaces:
interfaces
On the shell I did this operation :
cat > /root/pfsense-route.sh << EOF
#!/bin/sh
## IP forwarding activation echo 1 > /proc/sys/net/ipv4/ip_forward
## Rediriger les paquets destinés au LAN pour l'interface WAN de la PFSense ip route change 192.168.9.0/24 via 10.0.0.2 dev vmbr1 EOF
And I modified the file /etc/hosts :
[...]
auto vmbr2
iface vmbr2 inet static
address 192.168.9.1/24
bridge-ports none
bridge-stp off
bridge-fd 0
post-up /root/pfsense-route.sh
#LAN
And now the heart of the problem, the iptables. Here is my current file :
#!/bin/sh
# ---------
# VARIABLES
# ---------
## Proxmox bridge holding Public IP
PrxPubVBR="vmbr0"
## Proxmox bridge on VmWanNET (PFSense WAN side)
PrxVmWanVBR="vmbr1"
## Proxmox bridge on PrivNET (PFSense LAN side)
PrxVmPrivVBR="vmbr2"
## Network/Mask of VmWanNET
VmWanNET="10.0.0.0/30"
## Network/Mmask of PrivNET
PrivNET="192.168.9.0/24"
## Network/Mmask of VpnNET
VpnNET="10.2.2.0/24"
## Public IP => Your own public IP address
PublicIP="91.121.134.145"
## Proxmox IP on the same network than PFSense WAN (VmWanNET)
ProxVmWanIP="10.0.0.1"
## Proxmox IP on the same network than VMs
ProxVmPrivIP="192.168.9.1"
## PFSense IP used by the firewall (inside VM)
PfsVmWanIP="10.0.0.2"
# ---------------------
# CLEAN ALL & DROP IPV6
# ---------------------
### Delete all existing rules.
iptables -F
iptables -t nat -F
iptables -t mangle -F
iptables -X
### This policy does not handle IPv6 traffic except to drop it.
ip6tables -P INPUT DROP
ip6tables -P OUTPUT DROP
ip6tables -P FORWARD DROP
# --------------
# DEFAULT POLICY
# --------------
### Block ALL !
iptables -P OUTPUT DROP
iptables -P INPUT DROP
iptables -P FORWARD DROP
# ------
# CHAINS
# ------
### Creating chains
iptables -N TCP
iptables -N UDP
# UDP = ACCEPT / SEND TO THIS CHAIN
iptables -A INPUT -p udp -m conntrack --ctstate NEW -j UDP
# TCP = ACCEPT / SEND TO THIS CHAIN
iptables -A INPUT -p tcp --syn -m conntrack --ctstate NEW -j TCP
# ------------
# GLOBAL RULES
# ------------
# Allow localhost
iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
# Don't break the current/active connections
iptables -A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
iptables -A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
# Allow Ping - Comment this to return timeout to ping request
iptables -A INPUT -p icmp --icmp-type 8 -m conntrack --ctstate NEW -j ACCEPT
# --------------------
# RULES FOR PrxPubVBR
# --------------------
### INPUT RULES
# ---------------
# Allow SSH server
iptables -A TCP -i \$PrxPubVBR -d \$PublicIP -p tcp --dport 22 -j ACCEPT
# Allow Proxmox WebUI
iptables -A TCP -i \$PrxPubVBR -d \$PublicIP -p tcp --dport 8006 -j ACCEPT
### OUTPUT RULES
# ---------------
# Allow ping out
iptables -A OUTPUT -p icmp -j ACCEPT
### Proxmox Host as CLIENT
# Allow HTTP/HTTPS
iptables -A OUTPUT -o \$PrxPubVBR -s \$PublicIP -p tcp --dport 80 -j ACCEPT
iptables -A OUTPUT -o \$PrxPubVBR -s \$PublicIP -p tcp --dport 443 -j ACCEPT
# Allow DNS
iptables -A OUTPUT -o \$PrxPubVBR -s \$PublicIP -p udp --dport 53 -j ACCEPT
### Proxmox Host as SERVER
# Allow SSH
iptables -A OUTPUT -o \$PrxPubVBR -s \$PublicIP -p tcp --sport 22 -j ACCEPT
# Allow PROXMOX WebUI
iptables -A OUTPUT -o \$PrxPubVBR -s \$PublicIP -p tcp --sport 8006 -j ACCEPT
### FORWARD RULES
# ----------------
### Redirect (NAT) traffic from internet
# All tcp to PFSense WAN except 22, 8006
iptables -A PREROUTING -t nat -i \$PrxPubVBR -p tcp --match multiport ! --dports 22,8006 -j DNAT --to \$PfsVmWanIP
# All udp to PFSense WAN
iptables -A PREROUTING -t nat -i \$PrxPubVBR -p udp -j DNAT --to \$PfsVmWanIP
# Allow request forwarding to PFSense WAN interface
iptables -A FORWARD -i \$PrxPubVBR -d \$PfsVmWanIP -o \$PrxVmWanVBR -p tcp -j ACCEPT
iptables -A FORWARD -i \$PrxPubVBR -d \$PfsVmWanIP -o \$PrxVmWanVBR -p udp -j ACCEPT
# Allow request forwarding from LAN
iptables -A FORWARD -i \$PrxVmWanVBR -s \$VmWanNET -j ACCEPT
### MASQUERADE MANDATORY
# Allow WAN network (PFSense) to use vmbr0 public adress to go out
iptables -t nat -A POSTROUTING -s \$VmWanNET -o \$PrxPubVBR -j MASQUERADE
# --------------------
# RULES FOR PrxVmWanVBR
# --------------------
### Allow being a client for the VMs
iptables -A OUTPUT -o \$PrxVmWanVBR -s \$ProxVmWanIP -p tcp -j ACCEPT
For now with this I still manage to go on my VMs in proxmox, but I’m not internet access on it. Moreover, the shell of my server is no longer accessible on proxmox and SSH connections are no longer accessible.
Some details:
I use port 22 as ssh port
My server ip is 91.121.134.145
My version of linux is Debian 10 (Buster)
Honestly I don’t know where the problem comes from, I’m a beginner and I find the majority of this configuration on the internet. If you see what is wrong I would be very happy to have the answer! In the meantime I thank you in advance for your reading and your answers!
Edit :
I tried to pass the iptables in legacy mode using these commands :
update-alternatives --set iptables /usr/sbin/iptables-legacy
update-alternatives --set ip6tables /usr/sbin/ip6tables-legacy
update-alternatives --set ebtables /usr/sbin/ebtables-legacy
Only this command to refuse to work :
update-alternatives --set arptables /usr/sbin/arptables-legacy
Moreover I don’t know why but my VMs have good access to the internet, the problem is therefore centered on the SSH port that no longer works (I can no longer go on the shell since proxmox)