Rather suddenly my two satellite Decos will randomly drop off the Mesh and flash red, requiring a reboot. 
 

I have power cycled them. 
 

I have removed them and re-added them. 
 

At lease once a day this happens, usually multiple times a day. 
 

The main Deco maintains network connection to the internet and stays green.

All devices have the same firmware.

They worked like this for years without issue.

I am not sure what to try next, any suggestions are welcome.

additional note, they all live on the same floor of the house and it's not a big house.

Thanks!