diff --git a/roles/mongodb/defaults/main.yml b/roles/mongodb/defaults/main.yml
index a96fe6f99..1c54103e7 100644
--- a/roles/mongodb/defaults/main.yml
+++ b/roles/mongodb/defaults/main.yml
@@ -15,7 +15,7 @@
 
 # mongodb_enabled: False
 
-# mongodb_port: 27018
+# mongodb_port: 27017
 
 # All above are set in: github.com/iiab/iiab/blob/master/vars/default_vars.yml
 # If nec, change them by editing /etc/iiab/local_vars.yml prior to installing!
diff --git a/roles/mongodb/tasks/install.yml b/roles/mongodb/tasks/install.yml
index 71e111b2e..3f1eb6578 100644
--- a/roles/mongodb/tasks/install.yml
+++ b/roles/mongodb/tasks/install.yml
@@ -114,12 +114,12 @@
         - mongodb-org-server
       state: present
 
-  - name: Change {{ mongodb_conf }} port to {{ mongodb_port }} -- takes effect on next (re)start of the service -- via enable-or-disable.yml or via sugarizer.service auto-starting MongoDB on demand
+  - name: Establish {{ mongodb_conf }} port {{ mongodb_port }} (mongodb_conf) -- takes effect on next (re)start of the service -- via enable-or-disable.yml or via sugarizer.service auto-starting MongoDB on demand
     lineinfile:
       path: "{{ mongodb_conf }}"
-      regexp: "port: 27017"
-      backrefs: yes
-      line: "  port: {{ mongodb_port }}"    # 27018
+      regexp: '^\s*port:' # \s = any whitespace char. stackoverflow.com/a/38491899
+      #backrefs: yes
+      line: "  port: {{ mongodb_port }}"    # 27017
 
   # end block
   when: (ansible_architecture == "aarch64") or (ansible_architecture == "x86_64")
diff --git a/roles/mongodb/templates/mongod.conf.j2 b/roles/mongodb/templates/mongod.conf.j2
index 9d9c9c9c1..8d450c508 100644
--- a/roles/mongodb/templates/mongod.conf.j2
+++ b/roles/mongodb/templates/mongod.conf.j2
@@ -5,7 +5,12 @@
 # Comma separated list of ip addresses to listen on (all local ips by default)
 bind_ip = 127.0.0.1
 
-# Specify port number (27017 by default...but typically 27018 for IIAB)
+# mongodb_port is set to 27017 in /opt/iiab/iiab/vars/default_vars.yml
+# If you must change this, it's best to edit /etc/iiab/local_vars.yml prior to
+# installing IIAB.  Please also see upstream recommendations:
+# https://github.com/llaske/sugarizer-server/blob/master/env/sugarizer.ini line ~22 under [database]
+# https://docs.mongodb.com/manual/reference/default-mongodb-port/
+# https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.txt
 port = {{ mongodb_port }}
 
 # Fork server process (false by default)
diff --git a/roles/sugarizer/tasks/install.yml b/roles/sugarizer/tasks/install.yml
index f478457ff..ac490d70e 100644
--- a/roles/sugarizer/tasks/install.yml
+++ b/roles/sugarizer/tasks/install.yml
@@ -176,7 +176,7 @@
 - name: Set Sugarizer port to {{ sugarizer_port }} in /opt/iiab/sugarizer-server/env/sugarizer.ini
   lineinfile:
     path: "{{ iiab_base }}/sugarizer-server/env/sugarizer.ini"
-    regexp: "^port = 8080$"
+    regexp: '^port = 8080$'
     line: "port = {{ sugarizer_port }}"
 
 # 2019-02-02 No Longer Required thanks to @llaske's upstream fix:
@@ -193,15 +193,19 @@
 #- name: Set MongoDB "server" from localhost to 127.0.0.1 in /opt/iiab/sugarizer-server/env/sugarizer.ini
 #  lineinfile:
 #    path: "{{ iiab_base }}/sugarizer-server/env/sugarizer.ini"
-#    regexp: "^server = localhost$"
+#    regexp: '^server = localhost$'
 #    line: "server = 127.0.0.1"
 
-# mongodb_port is set to 27018 in /opt/iiab/iiab/vars/default_vars.yml
-# If you need to change this, edit /etc/iiab/local_vars.yml prior to installing
+# mongodb_port is set to 27017 in /opt/iiab/iiab/vars/default_vars.yml
+# If you must change this, it's best to edit /etc/iiab/local_vars.yml prior to
+# installing IIAB.  Please also see upstream recommendations:
+# https://github.com/llaske/sugarizer-server/blob/master/env/sugarizer.ini line ~22 under [database]
+# https://docs.mongodb.com/manual/reference/default-mongodb-port/
+# https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.txt
 - name: Set MongoDB port to {{ mongodb_port }} in /opt/iiab/sugarizer-server/env/sugarizer.ini
   lineinfile:
     path: "{{ iiab_base }}/sugarizer-server/env/sugarizer.ini"
-    regexp: "^port = 27017$"
+    regexp: '^port = 27017$'    # Careful as file also contains 2 other ports!
     line: "port = {{ mongodb_port }}"
 
 # 2-LINE FIX FOR sugarizer.js BY @georgejhunt FOR http://box/sugarizer
@@ -211,7 +215,7 @@
 - name: For http://box/sugarizer -- add pathPrefix lines in /opt/iiab/sugarizer-server/sugarizer.js
   lineinfile:
     path: "{{ iiab_base }}/sugarizer-server/sugarizer.js"
-    regexp: "AUTO-INSERTED BY IIAB"    # avoids inserting it twice!
+    regexp: 'AUTO-INSERTED BY IIAB'    # avoids inserting it twice!
     insertbefore: "// Start listening$"
     line: |    # SEE https://yaml-multiline.info (use |+ to 'keep' newlines at end...though |8 and |+4 "indentation indicators" don't work with Ansible)
       // AUTO-INSERTED BY IIAB FOR http://box/sugarizer
diff --git a/vars/default_vars.yml b/vars/default_vars.yml
index c71774088..916dbb88a 100644
--- a/vars/default_vars.yml
+++ b/vars/default_vars.yml
@@ -485,7 +485,7 @@ mongodb_install: False
 # misleading as Sugarizer starts mongodb's systemd service on its own, due to
 # 'Requires=mongodb.service' within /etc/systemd/system/sugarizer.service
 mongodb_enabled: False
-mongodb_port: 27018
+mongodb_port: 27017
 
 # roles/sugarizer/meta/main.yml auto-invokes 2 above prereqs: mongodb & nodejs
 # Might stall MongoDB on Power Failure: github.com/xsce/xsce/issues/879