Try removing --- from system.yml for Debian.

facts/system.yml

@@ -1,32 +1,30 @@
----
 # Define file, folder, and other facts per OS.
 
-- tasks:
-  - name: Set Pop OS Facts
-    ansible.builtin.set_fact:
-      flatpak_distro: yes
-      lynis_install_dir: /usr/local/lynis
-      lynis_report: /home/ling/lynis.log
-      sudoers_install_dir: /etc/sudoers.d/ansible
-      ansible_pull_exec: /usr/bin/ansible-pull
-    when: ansible_distribution == "Pop!_OS"
+- name: Set Pop OS Facts
+  ansible.builtin.set_fact:
+    flatpak_distro: yes
+    lynis_install_dir: /usr/local/lynis
+    lynis_report: /home/ling/lynis.log
+    sudoers_install_dir: /etc/sudoers.d/ansible
+    ansible_pull_exec: /usr/bin/ansible-pull
+  when: ansible_distribution == "Pop!_OS"
 
 
-  - name: Set Debian and Ubuntu Facts
-    ansible.builtin.set_fact:
-      flatpak_distro: yes
-      lynis_install_dir: /usr/local/lynis
-      lynis_report: /root/lynis.log
-      sudoers_install_dir: /etc/sudoers.d/ansible
-      ansible_pull_exec: /usr/bin/ansible-pull
-    when: ansible_distribution in ("Debian","Ubuntu")
+- name: Set Debian and Ubuntu Facts
+  ansible.builtin.set_fact:
+    flatpak_distro: yes
+    lynis_install_dir: /usr/local/lynis
+    lynis_report: /root/lynis.log
+    sudoers_install_dir: /etc/sudoers.d/ansible
+    ansible_pull_exec: /usr/bin/ansible-pull
+  when: ansible_distribution in ("Debian","Ubuntu")
 
 
-  - name: Set FreeBSD Facts
-    ansible.builtin.set_fact:
-      flatpak_distro: no
-      lynis_install_dir: /usr/local/lynis
-      lynis_report: /root/lynis.log
-      sudoers_install_dir: /usr/local/etc/sudoers.d/ansible
-      ansible_pull_exec: /usr/local/bin/ansible-pull
-    when: ansible_distribution == "FreeBSD"
+- name: Set FreeBSD Facts
+  ansible.builtin.set_fact:
+    flatpak_distro: no
+    lynis_install_dir: /usr/local/lynis
+    lynis_report: /root/lynis.log
+    sudoers_install_dir: /usr/local/etc/sudoers.d/ansible
+    ansible_pull_exec: /usr/local/bin/ansible-pull
+  when: ansible_distribution == "FreeBSD"