Ansible hangs using become when executed by jenkins user - jenkins

Question

Ansible playbook via Jenkins job
For my CI/CD pipeline, I'm using Jenkins to execute an Ansible playbook using the Ansible plugin. Jenkins and ansible are running on the same GCP instance (Debian 10). Ansible is running the playbook against another GCP instance (Also Debian 10) via the private network. When I run the playbook manually using my default GCP user, everything works flawlessly. However, when Jenkins is trying to run the playbook or when I'm running the playbook manually as the jenkins user, playbook execution hangs whenever become is set to yes.
Ansible stdout
22m 19s
[WindBox_main#2] $ ansible-playbook ./ansible/playbook.yml -i ./ansible/hosts
PLAY [all] *********************************************************************
TASK [Gathering Facts] *********************************************************
ok: [10.156.0.2]
TASK [docker_stack : Ping host] ************************************************
ok: [10.156.0.2]
TASK [docker_stack : Ping host with become] ************************************
I have the ansible become password stored in a vars file (I know, it should be in the vault), and I verified that ansible is able to access this variable. The private key used by ansible to establish an ssh connection has the same owner and group as the vars file and ssh connection is not a problem.
Manually establishing an ssh connection with the jenkins user and private key works as expected, so does the sudo command when logged in as the ansible-cicd user.
Initial research has pointed me towards this post, stating that the process running on the remote host might be waiting for user input, this does not seem likely as this is not happening when running as my default user. I assume that remotely everything is running as the ansible-cicd user, as specified in the hosts file.
I assume it is some sort of permission problem. It does not look like it's any of the files mentioned below. Is there something I am missing? Does ansible's become require local sudo access?
Any help would be greatly appreciated.
Files
hosts
[dockermanager]
10.156.0.2 ansible_user=ansible-cicd ansible_ssh_private_key_file=/var/lib/jenkins/.ssh/id_rsa
[dockermanager:vars]
ansible_python_interpreter=/usr/bin/python3
ansible_connection=ssh
playbook.yml
---
- hosts: all
vars:
ansible_python_interpreter: /usr/bin/python3
ansible_connection: local
vars_files:
- /etc/ansible/secrets.yml
roles:
- docker_stack
roles/docker_stack/main.yml (shortened for brevity, but these are the first 2 steps)
---
- name: Ping host
ansible.builtin.ping:
- name: Ping host with become
ansible.builtin.ping:
become: yes
/var/lib/jenkins/.ssh/
total 20
drwx------ 2 jenkins jenkins 4096 Nov 23 22:12 .
drwxr-xr-x 26 jenkins jenkins 4096 Nov 25 15:27 ..
-rw------- 1 jenkins jenkins 1831 Nov 25 15:19 id_rsa
-rw-r--r-- 1 jenkins jenkins 405 Nov 25 15:19 id_rsa.pub
-rw-r--r-- 1 jenkins jenkins 666 Nov 25 15:13 known_hosts
/etc/ansible/
total 16
drwxr-xr-x 2 ansible ansible 4096 Nov 24 13:42 .
drwxr-xr-x 80 root root 4096 Nov 25 15:09 ..
-rw-r--r-- 1 jenkins jenkins 62 Nov 24 13:42 secrets.yml

Answer 1

As mentioned by #mdaniel in the comments, the ansible_connection variable was defined twice (in hosts and in playbook) and ssh was overridden by local, meaning ansible never actually connected to my remote machine.
Removing ansible_collection: local from the playbook vars solved the problem.