Multiple WIFI on Raspberry pi Zero

I'm attempting to setup a Raspberry Pi zero W with an additional USB Wifi Dongle (wlan0 and wlan1) to connect to two different WIFI networks (one 2.4GHZ and the other 5GHZ).

OS information:

"Raspbian GNU/Linux 10 (buster)"Linux hades 5.10.23+ #1406 Mon Mar 15 15:37:16 GMT 2021 armv6l GNU/Linux

Raspberry Pi OS seems to have moved away from what I expected in /etc/network/interfaces and getting them both to connect to two different networks is challenging. I used online guides I found using internet searches but sadly they appear to be for legacy versions of Raspbian rather than the current Raspberry Pi OS and don't work.

e.g.https://mikestreety.medium.com/use-a-raspberry-pi-with-multiple-wifi-networks-2eda2d39fdd6

I've no issue in setting up the RPI with a single Wifi device on either network via wpa_supplicant.conf. But when I put in two networks into wpa_supplicant.conf I get both devices join the same SSID on different IP addresses.

Default /etc/network/interfaces

# interfaces(5) file used by ifup(8) and ifdown(8)# Please note that this file is written to be used with dhcpcd# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'# Include files from /etc/network/interfaces.d:source-directory /etc/network/interfaces.d

Attempted interfaces:-

auto loiface lo inet loopbackauto wlan0allow-hotplug wlan0iface wlan0 inet mannualwpa-roam /etc/wpa_supplicant/wpa_supplicant.confauto wlan1allow-hotplug wlan1iface wlan1 inet manualiface safe inet dhcpiface full inet dhcp

I've solved the issue (detailed as an answer) by installing and configuring netplan but I was wondering if anyone knew how to configure multiple wifi network without using netplan?