@JDF1 

Hi, thank you very much for your kind feedback.

I would like to forward your case to the senior engineers for further assistance.

Since it might take almost 6 weeks to repeat again, would you please help me check the following information when it started again:

1. When the main Deco lost the connection and turned red, please go to Deco APP>More>Advanced>IPV4 and save a picture of this page;

(while if Deco APP said 'we couldn't find Deco', please make sure the smartphone was still connected to Deco and get the correct IP address, like 192.168.68.xxx)

2. then please go to http://tplinkdeco.net and save the system log on the Deco, for example:

https://www.tp-link.com/en/support/faq/2641/

Thanks a lot.