Can't Get Pi to Forward port (Network)

Question

I've got a port forwarding issue on my Pi.

I have 2 Pi's running and listening with the same server software, Pi's listening respective on ports ie 8005 and 8006, one pi has 8005 and the other 8006 to serve a streaming Pi cam page.

I have my router setup the same for both these ports, but only one port forwards OK to WAN.

I can see each pi's page OK when I visit Locally on the routers network, but only one of the Pis forward outbound to the public IP my router is connected to. The other timesout when I visit it's page. No HTTPS setup.

I'm unsure the diagnostics steps and settings / things to check to isolate this issue. I wouldn't put it past the router to be funky, but I speculate it's working, since it's only selective to not work on that particular Pi's configuration.

I tried changing ports, nothing. Isolated just the 'bad' pi, removing all fwd settings in the router but that one, same results.

iptables -L shows nothing. I know some of the network settings was tinkered with in the past so the Pi would create its own AP when not connected to a specific wpa_supplicant, so maybe somewhere in there my network settings are off.

I may need to raise this question within the linux networking StackExchange realm, but since it's Pi related, I'd thought I'd start here first.

Working Pi : ip addr - returns:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
       link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
       inet 127.0.0.1/8 scope host lo
          valid_lft forever preferred_lft forever
       inet6 ::1/128 scope host
          valid_lft forever preferred_lft forever
   2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
       link/ether b8:27:eb:37:77:12 brd ff:ff:ff:ff:ff:ff
       inet6 fe80::26cb:1dca:3b32:c6f3/64 scope link tentative
          valid_lft forever preferred_lft forever
   3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
       link/ether b8:27:eb:62:22:47 brd ff:ff:ff:ff:ff:ff
       inet 192.168.0.9/24 brd 192.168.0.255 scope global wlan0
          valid_lft forever preferred_lft forever
       inet6 fe80::e4d4:413a:11ba:7cb9/64 scope link
          valid_lft forever preferred_lft forever

Failing Fwd Pi returns:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
    link/ether b8:27:eb:83:63:37 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::6e1d:3c1d:367d:c31d/64 scope link tentative
       valid_lft forever preferred_lft forever
3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether b8:27:eb:d6:36:62 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.29/24 brd 192.168.0.255 scope global wlan0
       valid_lft forever preferred_lft forever
    inet6 fe80::aaba:7f60:b76a:6f4/64 scope link
       valid_lft forever preferred_lft forever

ip route:

Working pi:

default via 192.168.0.1 dev wlan0  metric 303
192.168.0.0/24 dev wlan0  proto kernel  scope link  src 192.168.0.9  metric 303

Failing Fwd Pi:

default via 192.0.0.1 dev wlan0  metric 303
192.0.0.1 dev wlan0  scope link  metric 303
192.168.0.0/24 dev wlan0  proto kernel  scope link  src 192.168.0.29  metric 303