Multiple variables in with_items made error - ansible

Question

I created the following playbook to set ufw settings.
---
- name: setup ufw for multi ports
hosts: db
become: yes
tasks:
- name: 'Allow all access for multi ports'
community.general.ufw:
rule: allow
port: "{{ item.port_num }}"
src: "{{ item.dest_ip }}"
with_items:
- { port_num: "33787", dest_ip: "{{web_ip_band}}" }
And this is my group_vars file.
web_ip_band:
- '192.168.101.13/24'
- '192.168.101.44/24'
when I execute this playbook, I get this error.
failed: [dbserver01] (item={'port_num': '33787', 'dest_ip': ['192.168.101.13/24', '192.168.101.44/24']}) => {"ansible_loop_var": "item", "changed": false, "commands": ["/usr/sbin/ufw status verbose", "/bin/grep -h '^### tuple' /lib/ufw/user.rules /lib/ufw/user6.rules /etc/ufw/user.rules /etc/ufw/user6.rules /var/lib/ufw/user.rules /var/lib/ufw/user6.rules", "/usr/sbin/ufw --version", "/usr/sbin/ufw allow from ['192.168.101.13/24', '192.168.101.44/24'] to any port 33787"], "item": {"dest_ip": ["192.168.101.13/24", "192.168.101.44/24"], "port_num": "33787"}, "msg": "ERROR: Wrong number of arguments\n"}
Is there a syntax error in my playbook?

Answer 1

From the community.general.ufw module documentation (extract rearranged to fit in SO answer)
from_ip (aliases: from, src)
string - Default: "any"
You are passing a list of IPs, which explains your error message:
ERROR: Wrong number of arguments
You have to play that task for each combination of port_num and individual entries in dest_ip. What you need here is a subelements loop:
- name: 'Allow all access for multi ports'
community.general.ufw:
rule: allow
port: "{{ item.0.port_num }}"
src: "{{ item.1 }}"
vars:
my_rules:
- { port_num: "33787", dest_ip: "{{web_ip_band}}" }
loop: "{{ my_rules | subelements('dest_ip') }}"