Connect Multiple Interfaces on Raspberry Pi

I use my raspi as a local DNS resolver (Pi-hole). My router has 2 networks "Home" & "Guest". As usual, the guest client can't reach my raspi as it is on the home network so the internet doesn't work for guest clients. So I plugged in a USB wifi adapter to connect it to the guest network so it could talk to the guest clients from there. But the issue is after setting up the Netplan it connects to the guest network but for some reason, I can ping the guest IP of raspi from the home network & the guest client still can't reach it. My router can see it with the home network IP !! Need help to fix this issue, noob here.

Information:

Home Network: | Interface: eth0 | IP: 192.168.68.104

Guest Network: | Interface: wlan0 | IP: 192.168.68.204

/etc/netplan/50-cloud-init.yaml:

network:
  version: 2
  ethernets:
    eth0:
      dhcp4: false
      addresses: [192.168.68.104/24]
      routes:
       - to: default
         via: 192.168.68.1
         metric: 200
      nameservers:
        addresses: [127.0.0.1]
  wifis:
    wlan0:
      dhcp4: false
      addresses: [192.168.68.204/24]
      routes:
       - to: default
         via: 192.168.68.1
         metric: 300
      nameservers:
        addresses: [127.0.0.1]
      access-points:
          "Guest Network Name":
              password: "Guest Password"

ifconfig:

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.68.104  netmask 255.255.255.0  broadcast 192.168.68.255
        inet6 fe80::ba27:ebff:fe3c:bddd  prefixlen 64  scopeid 0x20<link>
        ether b8:27:eb:3c:bd:dd  txqueuelen 1000  (Ethernet)
        RX packets 391049  bytes 44256085 (44.2 MB)
        RX errors 0  dropped 7  overruns 0  frame 0
        TX packets 357415  bytes 41832959 (41.8 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        
wlan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 2312
        inet 192.168.68.204  netmask 255.255.255.0  broadcast 192.168.68.255
        inet6 fe80::523e:aaff:fe6c:6966  prefixlen 64  scopeid 0x20<link>
        ether 50:3e:aa:6c:69:66  txqueuelen 1000  (Ethernet)
        RX packets 20534  bytes 2926374 (2.9 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2567  bytes 265318 (265.3 KB)
        TX errors 0  dropped 7 overruns 0  carrier 0  collisions 0

ip route list:

default via 192.168.68.1 dev eth0 src 192.168.68.104 metric 202 
default via 192.168.68.1 dev wlan0 proto dhcp src 192.168.68.112 metric 303
192.168.68.0/24 dev eth0 proto dhcp scope link src 192.168.68.104 metric 202 
192.168.68.0/24 dev wlan0 proto dhcp scope link src 192.168.68.112 metric 303

Router DHCP Server Settings: Router DHCP Screenshot