If you do not see a "Cameras" menu option in addition to the "Switch" menu then perhaps the cameras are in a different network. If you want them in the same Dashboard network, select the network drop down and choose "view all networks" and select both and click the combine button.
This sounds like it's something upstream related. Have you had a chance to confirm the cameras have the proper outbound connectivity to communicate with Dashboard? Is there an alternate VLAN you can place them on, perhaps temporarily, with open Internet access, just to rule out an upstream ACL or firewall or NAT boundary issue?
If the cameras are getting a DHCP address on the correct VLAN and are pingable, it's pointing to an upstream issue. Many times it's plug and play if outbound traffic is allowed by default and your stateful firewalls naturally allow the reverse inbound traffic. But in some environments with more restrictive firewall policies, where even outbound access is restricted by default, you may need to open some ports to specific subnets in the Meraki cloud.
Meraki Dashboard has a self-maintaining spreadsheet of exactly what rules would be allowed, based on what you have deployed and what features you have enabled. You'll see it under Help > Firewall Info.
One other thought, in addition to pinging between the switch and the camera, can you get positive reaults when you select "Ping Camera" from the Dashboard itself?
Point taken on the documentation, I've mentioned in the past this should be a footnote in the various installation guides, I think I've perhaps seen it referenced in some, but definitely not in others. Will remind the documentation team.