I have two Deco X55 satellites (with one base node) that have been relatively stable for months. In the last few weeks, they've both started flashing red unpredictably and/or the Deco app says one or both of them is down.

This week, they've started continuously flashing red. I've rebooted the satellites, rebooted the entire network (including restarting the ISP modem. 
 

I haven't changed anything about the network or hardware other than to install TP-Link firmware updates as available.

How do I get tech support from TP-Link on this?