My SmartPlus app always worked well before, but last week, I can initiate the call from the app, but can not see the video.  I have checked my smartphone camera permission for the app, it is normal. And I am quite sure the camera of the door phone is working well， because I can see the video on my indoor monitor. Finally, I found that I have adjusted different video codecs in the indoor monitor last week， because I need to test the video quality. And after I consulted the support, they told me only VGA codec can be supported if I use SmartPlus cloud. As have and I haven’t done anything in the cloud portal, the configuration would not be issued again to the device, so that’s why the local configuration was still available.

That is my experience, I think it may be useful for you all.

camera permission is always enabled

codec is not VGA

After the cloud issues the configuration again.  the codecs show VGA, the video is normal.