Unable to access variable value inside nested if statement in bash

Question

I am trying to write a bash script that takes advantage of libvirt hooks to set the vlan on the vm is connected to (using openvswitch). The challenge however is using the portAssigned variable inside the nested if statement, everything I've tried so far has failed. I can see the variable outside the if statement but within it, it is empty, however the portNumber variable works fine, how do I pass in $portAssigned variable to the inside if statement?

$ bash --version
GNU bash, version 5.1.8(1)-release (x86_64-pc-linux-gnu)
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>

This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

#!/bin/bash

portNumber=$(cut -d "_" -f2 <<< "$1")
domainXML=`cat /dev/stdin`
portAssigned=`echo "$domainXML" |  xmllint --xpath 'string(//domain/devices/interface[@type="bridge"]/target/@dev)' -`
DATE=$(date)
echo $domainXML | tee /home/generic_vm/domainXML.txt
echo $portAssigned | tee -a /home/generic_vm/domainXML.txt

if [ "$1" = "gene01_16" ]; then
  if [ "$2" = "prepare" ]; then
    echo "True" > /home/generic_vm/libvirt_hook.txt
    ovs-vsctl set port $portAssigned tag=$portNumber
    echo "Creating port in Openvswitch bridge for vm: $1, tag: ${portNumber}, portname: $portAssigned at ${DATE}" | tee -a /home/generic_vm/libvirt_hook.txt
  fi
elif [ "$1" = "gene01_16" ]; then
  if [ "$2" = "release" ]; then
    ovs-vsctl del-port br0 $portAssigned
    echo "Deleting port in Openvswitch bridge for vm: ${vm}, portname: $portAssigned at ${DATE}" | tee -a /home/generic_vm/libvirt_hook.txt
  fi
fi

$ cat domainXML.txt 
<domain type='kvm' id='88'> <name>gene01_16</name> <uuid>d1876d79-7fea-42b1-bd27-62a71809afaa</uuid> <memory unit='KiB'>524288</memory> <currentMemory unit='KiB'>524288</currentMemory> <vcpu placement='static'>1</vcpu> <resource> <partition>/machine</partition> </resource> <os> <type arch='x86_64' machine='pc-i440fx-impish'>hvm</type> <boot dev='hd'/> </os> <features> <acpi/> <apic/> <pae/> </features> <cpu mode='host-passthrough' check='none' migratable='on'/> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>destroy</on_crash> <devices> <emulator>/usr/bin/qemu-system-x86_64</emulator> <disk type='file' device='cdrom'> <driver name='qemu' type='raw'/> <source file='/mnt/sdadisk/default/commoninit.iso' index='1'/> <backingStore/> <target dev='hdd' bus='ide'/> <readonly/> <alias name='ide0-1-1'/> <address type='drive' controller='0' bus='1' target='0' unit='1'/> </disk> <controller type='usb' index='0' model='piix3-uhci'> <alias name='usb'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/> </controller> <controller type='pci' index='0' model='pci-root'> <alias name='pci.0'/> </controller> <controller type='ide' index='0'> <alias name='ide'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/> </controller> <controller type='virtio-serial' index='0'> <alias name='virtio-serial0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> </controller> <interface type='bridge'> <mac address='52:54:00:d2:2a:3a'/> <source network='br0' portid='acafb864-bcdb-4151-a3c7-40cb775f3a97' bridge='br0'/> <virtualport type='openvswitch'> <parameters interfaceid='bc652b84-773f-4924-a231-7151c01a9651'/> </virtualport> <target dev='vnet48'/> <model type='virtio'/> <alias name='net0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> <channel type='unix'> <source mode='bind' path='/var/lib/libvirt/qemu/channel/target/domain-88-gene01_16/org.qemu.guest_agent.0'/> <target type='virtio' name='org.qemu.guest_agent.0' state='disconnected'/> <alias name='channel0'/> <address type='virtio-serial' controller='0' bus='0' port='1'/> </channel> <input type='mouse' bus='ps2'> <alias name='input0'/> </input> <input type='keyboard' bus='ps2'> <alias name='input1'/> </input> <graphics type='spice' port='5906' autoport='yes' listen='127.0.0.1'> <listen type='address' address='127.0.0.1'/> </graphics> <audio id='1' type='spice'/> <video> <model type='cirrus' vram='16384' heads='1' primary='yes'/> <alias name='video0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </video> <memballoon model='virtio'> <alias name='balloon0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> </memballoon> <rng model='virtio'> <backend model='random'>/dev/urandom</backend> <alias name='rng0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> </rng> </devices> <seclabel type='dynamic' model='apparmor' relabel='yes'> <label>libvirt-d1876d79-7fea-42b1-bd27-62a71809afaa</label> <imagelabel>libvirt-d1876d79-7fea-42b1-bd27-62a71809afaa</imagelabel> </seclabel> <seclabel type='dynamic' model='dac' relabel='yes'> <label>+64055:+108</label> <imagelabel>+64055:+108</imagelabel> </seclabel> </domain>
vnet48