I realize that this is a little late after the original post, but I thought that I might offer some insights from our experiences that seem to persist with the Meraki Video Wall problems even late into 2019.
What we did not discover until after our purchase was that the video walls do not make good 24/7 monitoring systems unless you have a pretty beefy system. The system resources being used are substantial and grow significantly with each camera added. It doesn't matter which browser you use, they all exhibit the same issues regardless of the underlying OS builds, driver sets, etc.
Once you buy enhanced systems with discrete video cards, you will still have issues but not as frequently. Our staff were complaining of having to frequently "reload" the video wall.
We created an app that would go into the browser session and periodically back out of it at 15 minute intervals and then re-enter the video wall automatically. While not a perfect solution, it cut down on the "reload"requests by about 95-98% in Chrome. We are about to change the refresh to about 10 minutes to see if that completely corrects the issue.
We are a small shop and don't have time to figure out what sort of cache or resource is crapping out or if it is some sort of memory leak inherent to how the video wall works ... but before you buy any cameras, make meraki sales prove the video wall works 24/7 on your systems. We don't use rotating video walls so that may not be an issue for that methodology since the screens are refreshing when the next rotation loads.
Oh - the cameras cannot be assigned static IPs (which we found out when took delivery of them). What a bunch of BS. I can assign an IP to my $10 toothbrush. Not being to assign a static IP is a huge pain in the ass (and no, I shouldn't have to create separate subnets blah blah blah just to add a high-dollar network device)