What you are experiencing is the HLS delay (HTTPS Live Streaming) which is normal and results in about a minimum of 4 to 5 seconds of delay because HLS turns the live video stream into a set of 2-second chunks and does sequential HTTP-based file downloads, and needs at least the first 2 chunks (about 4 seconds) to begins the streaming process. Meraki has optimized HLS for MV quite a bit, I believe it was originally well over 15 to 20 seconds.
The trade-off is that Meraki MV is extremely intuitive and simple to use, natively traverses any firewalls or proxies that allow HTTP in the first place, and requires no special software or browsers or specific Java versions or plugins or ActiveX controls or any of that. It's pretty much any browser on any device on any operating system and you're working with the full power of MV.
There is a setting that can help just a little, change the quality setting on the "Quality & Retention" page from Enhanced to Standard and this can shave off 1-2 seconds. This can slightly change the way the video is encoded as the stream gets split into files for the HLS stream. This setting can be camera by camera as well, so if the camera is zoomed in for identity of someone being buzzed in through a doorway, the quality may not matter much but the extra 1-2 seconds can really help whoever needs to see who is standing there before buzzing them in.
Unfortunately there will always be some HLS delay (remember the tradeoff: powerful, simple & intuitive with no special software or plugins) and it's already been optimized about as much as it can be. If it were to be optimized even further, it would introduce a lot more overhead, such as more numerous smaller video chunks therefore a higher percentage of protocol overhead, and could also introduce more of a chance for choppy video playback.
So be aware that users will have that perception that the cameras are just plain slow, they wave their hand in front of the camera and see it in Dashboard 6 to 8 seconds later and say "see how slow it is" but once they understand the architecture and the benefits and the reasons why there is a lag time, the HLS delay is typically an acceptable tradeoff.
All that said, it doesn't fit every single use case. Please continue to make wishes in Dashboard and share your use cases and requirements with your Meraki or Meraki Partner reps so they can filter these back to the product team to consider and prioritize feature development.
