Dahua 5231? I use IE for my 5231's and I get blue IVS lines. None on Firefox or Pale Moon. Something is amiss. Re-check please?
IE (notice how the image is always fubar'd such as being off center when using IE and older Dahua GUI menus...always happens to me):
Chrome:
Can't speak of why you have IVS1 and IVS2 for rule names. Different firmware? Did you purchase your cameras from Andy here on IPCT or from Aliexpress?
(again...IE is the only way to see IVS lines on live stream, but the image is always off-center for me and blocks menu options...grrrrr).
While I was able set up IVS rules in the other browsers, IE appears to be essential for successfully getting IVS to actually work (for this particular camera & firmware version at least.)
Updating the firmware appears to be the reason the IE plugin worked THIS TIME. It never worked for this cam before, and so I incorrectly assumed It would not work again... Now I’m supicious that using other browser(s) played a role in this camera’s instability.
It’s frustrating to deal with browser plug-ins that work for one camera, and don‘t for another. Lesson learned - just because the browser opens the camera, doesn’t mean everything’s working under the hood.