Cameras do not work if Internet down?

I know the base station has a cellular device in case Internet goes down, but to have the cameras unreachable when Internet is down doesn't make sense. Doesn't the cellular radio have enough bandwidth to handle the camera videos? The cameras should still function if the WLAN is up and I'm connected with the SS app. I understand if they cannot send videos to the "cloud" if the cell is 2G or something, but to have them just not function is unacceptable. Basic networking 101. I have several smart cameras I built from scratch hardware/software and they do not rely on the internet, so at least those still worked when SS cameras were offline.

Also, after the Internet came back up the cameras were still offline. I restarted the router and things started working again even though I verified the Internet was up first. Not real happy.