Because I hate myself, I updated the firmware back to 2022-8-18 on one camera only.
I got IVS triggers to work when I turned off authentication for ONVIF. For some reason BI is not accepting the ONVIF password or the camera is not sending it on the newer firmware. I updated to the latest version of BI today. I know the ONVIF password has been an issue for some, and I did attempt to address that, see below the picture.
As mentioned in my first post and will expand here, I used the admin profile in BI. After a factory reset, noticing that IVS triggers would not work in BI, I logged into the camera and reset the ONVIF password to "match" the admin password - so basically no change. I did try making another user at some point today and when I tried that IVS triggers didn't work either.
I tried Edge in IE mode.
I did a comparison between the older firmware and the newer firmware. The only notable difference in default settings is that people counting is on in the newer firmware but I don't see how that would affect IVS triggers. More notably for me, it looks like IR is turned off by default in the older firmware so that will be fun to see what happens later. I believe the newer firmware fixed an issue with IR, which is important to me.
It is about to storm here so I have to stop testing. Plus, the wife will be upset if I spend another evening on the computer working on cameras. I think I have been working on this since Friday.