Two eero 6+ devices dropped network connections - Why don't they restart by themselves?

My eero network consists of two eero Pro 6E devices (one being the gateway), two eero 6+ devices, and one eero extender.

The other day, I was on the eero app looking at the devices connected to one of the 6+ devices when suddently all the devices disappeared from that particular 6+. When back to the main page of the app and noticed that both 6+ units had gone off-line. 

So I waited for quite awhile thinking that the 6+ would restart themselves, but no, nothing. Eventually I had to do a manual restart by disconnecting the power to each eero 6+. They came back up OK, and reconnected to the mesh and everything is fine.

My question is this: why the heck don't these units recognize there is a problem after a certain period and restart themselves? Self-healing so to speak. Actually cannot believe these units do not automatically reboot when there is an issue. Is this something eero might be working on?