Network UPS Tool Setup Help

Hi,
I am trying to get NUT working correctly on a setup I am attempting to…setup.
 
The issue I am having is that none of the devices connected to the NUT server are doing what they are told.
For example, I have set (on a test system), that particular system to shutdown when the battery gets to 99%, and a second test system set to shutdown at 90%.
 
If I remove the power (other than this brand new UPS immediately dropping to 80%!!!) neither system shuts down, but does immediately receive a syslog message about the UPS being on battery.
Now, I am not confident i have my configs setup correctly.
 
Config wise -

Server Config (this is on a RaspberryPi/Home Assistant OS/NUT Addon, so its all YAML) -

    devices:
      - name: CyberPower-750VA-SL750U
        driver: usbhid-ups
        port: auto
        config:
          - vendorid = 0764
    mode: netserver
    shutdown_host: "false"
    users:
      - username: username
        password: password
        instcmds:
          - all
        actions:
          - set
    upsd_maxage: 25
    upsd_pollinterval: 15
    upsmon_deadtime: 60
    upsmon_pollfreq: 5
    upsmon_finaldelay: 60
    upsmon_notifyflag: 50
    upsmon_notifycmd: echo 'UPS has reached 50% remaining power' | wall
    log_level: debug

From what I can tell with the YAML here, the preceding upsd_ & upsmon_'s are just passing through whatever is after that into the relevant files in the NUT container it spins up in the background.
I have the notifycmd set to ‘WALL’ as I dont want the server to control the shutdown of the devices, as I want each to shutdown at different percentages, not have everything shutdown based on whatever variable its working off by default (also an unknown…).
 

Client Config
nut.conf

    MODE=netclient

upsmon.conf

    MINSUPPLIES 1
    SHUTDOWNCMD "/sbin/shutdown -h +0"
    POLLFREQ 15
    POLLFREQALERT 5
    DEADTIME 45
    MONITOR [email protected] 1 username password slave
    NOTIFYFLAG 99   SYSLOG+EXEC
    FINALDELAY 120
    
    # Other Options - defaults from example config
    HOSTSYNC 15
    POWERDOWNFLAG /etc/killpower
    RBWARNTIME 43200
    NOCOMMWARNTIME 300

The logic in this example client config is that when the power gets to 99%, the shutdown will begin.
Instead, what seems to happen is that the client seem to generate the [email protected] on battery in their service log, then nothing else happens. So they are clearly communicating with the server.
 
Is anyone able to help advise what I’m doing wrong here?
 
If i can get this explained, working, I plan to submit a PR to the doc page for this addon to add sorely missing content, as right now its…not great.
 
Thanks!