Suricata Custom Ruleset will not Load into `suricata.rules` - rules

Question

I am running Suricata in IDS (af-packet) mode on Ubuntu 20.04.5 LTS (Focal Fossa) and deployed as the root user:
NAME="Ubuntu"
VERSION="20.04.5 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04.5 LTS"
VERSION_ID="20.04"
Following the Suricata "Adding your own Rules" Doc, I have added a very basic (for complexity ease when troubleshooting) alerting-rule with first available sid:1000000 from custom rules range:
########### Test Rules #############
alert ssh any any -> xxx.xxx.60.6 !22 (msg:"SSH TRAFFIC on non-SSH port"; flow:to_client, not_established; classtype: misc-attack; target: dest_ip; sid:1000000;)
The .rules file for the local rules has sufficient permissions and matches suricata.rules, owned by root:
ls -halt /var/lib/suricata/rules/
total 22M
-rw-r--r-- 1 root root 3.2K Oct 17 00:00 classification.config
drwxr-x--- 2 root root 4.0K Oct 17 00:00 .
-rw-r--r-- 1 root root 22M Oct 17 00:00 suricata.rules
-rw-r--r-- 1 root root 210 Oct 13 21:45 local.rules
Ensured that the rules are added to Suricata suricata.yaml config and processed is restarted:
cat /etc/suricata/suricata.yaml | grep "rule-files" -A 5 -B 5
##
#default-rule-path: /var/lib/suricata/rules
default-rule-path: /etc/suricata/rules
rule-files:
- suricata.rules
- /var/lib/suricata/rules/local.rules
- /etc/suricata/rules/*.rules
AFAIK, the custom ruleset should be loaded into the suricata.rules file? Therefore, I am running the following verification subject to what I am reporting:
cat /var/lib/suricata/rules/suricata.rules | grep sid:1000000
I can test traffic and verify with tcpdump, matching the rule but never see a signature match in fast.log (which is logging other signature-matching traffic):
cat /var/log/suricata/fast.log | grep 1000000
I see no errors following statup of the service that would indicate an error present:
systemctl status suricata.service
● suricata.service - LSB: Next Generation IDS/IPS
Loaded: loaded (/etc/init.d/suricata; generated)
Active: active (running) since Mon 2022-10-17 13:11:39 UTC; 8h ago
Docs: man:systemd-sysv-generator(8)
Process: 2184275 ExecStart=/etc/init.d/suricata start (code=exited, status=0/SUCCESS)
Tasks: 78 (limit: 618963)
Memory: 25.2G
CGroup: /system.slice/suricata.service
└─2184295 /usr/bin/suricata -c /etc/suricata/suricata.yaml --pidfile /var/run/suricata.pid --af-packet -D -v>
Oct 17 13:11:39 sec3 systemd[1]: Starting LSB: Next Generation IDS/IPS...
Oct 17 13:11:39 sec3 suricata[2184275]: Starting suricata in IDS (af-packet) mode... done.
Oct 17 13:11:39 sec3 systemd[1]: Started LSB: Next Generation IDS/IPS.
Can somebody help me with somewhere I may be silly here?
TYIA!