Intermittent Internet connectivity - Proxmox + OpnSense (Hetzner)

[durlabh]

I've tried multiple machines and continue to have issues with Proxmox + OpnSense (or Pfsense). From the OpnSense host, internet connectivity seems intermittent. Even on curl for www.google.com, sometimes, it is in instantaneous and sometimes times out.

My host /etc/network/interfaces look like this:

source /etc/network/interfaces.d/*

auto lo
iface lo inet loopback

iface lo inet6 loopback

auto eno1
iface eno1 inet static
        address 162.55.193.xxx/26
        gateway 162.55.193.xxx
        post-up sysctl -w net.ipv4.ip_forward=1
        post-up iptables -t nat -A PREROUTING -i eno1 -p tcp -m multiport ! --dport 22,8006 -j DNAT --to 192.168.152.1
        post-up iptables -t nat -A PREROUTING -i eno1 -p udp -j DNAT --to 192.168.152.1

iface eno1 inet6 static
        address 2a01:4f7:xxxx:24cf::2/64
        gateway fe80::1

auto eno1.4000
iface eno1.4000 inet static
        address 192.168.141.212/24
        mtu 1400

auto vmbr0
iface vmbr0 inet static
        address 192.168.152.0/24
        bridge-ports none
        bridge-stp off
        bridge-fd 0
        post-up         iptables -t nat -A POSTROUTING -s '192.168.152.0/24' -o eno1 -j MASQUERADE
        post-down       iptables -t nat -D POSTROUTING -s '192.168.152.0/24' -o eno1 -j MASQUERADE

#OPNSense WAN - Proxmox LAN

auto vmbr1
iface vmbr1 inet manual
        ovs_type OVSBridge
#VM Net

In OpnSense, my network is setup as:

WAN = vmbr0 = 192.168.152.1
LAN = vmbr1

The curl command I'm executed is on OpnSense shell itself.

Any help is highly appreciated