Can you ping your broker’s IP address from Home Assistant (in a terminal addon)?
Can you publish to topics from your broker (dev tools → services)?
EDIT: sorry Nick that was meant to be a reply to Andrew.
I figured 
“Triggered manually” is a misnomer. The procedure simply executes the automation’s actions and never exercises any of the automation’s triggers. It proves nothing about the trigger’s health only the actions.
So far, it looks like you don’t have Home Assistant connected to your MQTT broker.
If you restart the broker and then check its log, you should see a record of all the clients that automatically login to it. Home Assistant should be one of them. If there’s no record of it in the broker’s log then Home Assistant isn’t connecting to the broker.
Yeah, I went through the setup process already.
But if I do a “Test” run on blue iris, I’m not sure what packets it sends but it will show up in the log for Mosquitto broker
But the MQTT topic that I made will not show on that log when I test it.
Restart the broker and confirm its log shows Home Assistant is logging in.
I tried Administrative privileges with the user I assigned to the MQTT user I made for this already, but it didn’t change anything, unfortunately.
Any evidence that the user account you created is automatically logging into the broker?
The screenshot of the broker’s log doesn’t appear to show any evidence of it.
Are you using the mqtt addon, or did you install an mqtt broker some other way?
What do you see when you look at your broker’s logs? Is home assistant connecting? Is blue iris connecting?
I thought I’d just have the same IP address as HA?
I can find the script under services on that page, but the call wont work without the automation calling it.
That would depend on which Broker you are using. I’m going to guess the Mosquitto addon. Is that correct?
You should be able to. Scripts are services. But I was talking about the mqtt publish service.
I just followed this guide when installing the MQTT broker.
Same thing tom posted
That button leads to where you enter the account and password that Home Assistant will use to login to core-mosquitto which is how the broker is identified when you install it as an Add-on.
Confirm it contains the correct User account and password that you created in Settings > People > Users.
For example, I have created several User accounts (no adminstrative privileges) that are dedicated for logging in to the MQTT broker. One is assigned to Home Assistant, another for Tasmota devices, another I use for MQTT Explorer, etc.
I kinda want to know what that client was that tried to connect at 18:19:32 because it was refused connection as it was unauthorised, and that 172 address it was connecting from is very docker. I’d definitely suspect that that was Home Assistant trying to connect to the broker and being rejected.
Are you telling me the login details for the Blue Iris account need to be configured in that? Or is the account that I made for the MQTT broker that had to be made for HA to use?
I’ve heard that this is supposed to be some kindof “heart beat” system and was told that it is normal. But I saw that too.
All I know is that it’s not Blue iris, lol. I’m on a 10.0.0.0 network.
The Blue Iris connection is being refused. So yes you need to set the login credentials correctly there.
Supervisor watchdog connection?
I thought Blue Iris was connected to MQTT because we saw the MQTT data in the MQTT Explorer screenshot. My working assumption is that it’s Home Assistant that is actually not connected to the MQTT Broker.
Yeah, I believe so.
Yeah scrap that last message from me. I misread the log.
Watchdog connection looks like this:
2023-12-30 09:50:20: New connection from 172.30.32.2:41752 on port 1883.
2023-12-30 09:50:20: Client <unknown> closed its connection.
2023-12-30 09:52:20: New connection from 172.30.32.2:55136 on port 1883.
2023-12-30 09:52:20: Client <unknown> closed its connection.
2023-12-30 09:54:20: New connection from 172.30.32.2:40846 on port 1883.
2023-12-30 09:54:20: Client <unknown> closed its connection.
It is home assistant that is not authorised.