Same issue here.  I have the MK63S AX1800 Router with 2 satellite extenders.  I unplugged and rebooted the router and the 2 extenders multiple times and even reset and attempted to set the entire system up again with no luck.  It is just 8 months old.  

What makes it worse is that when I attempted to get support through the app, it shows my warranty is through May 14, 2022 but gives me no way to actually communicate with Netgear to get support.  Please help.

I think my problem is similar.  A few days ago, I noticed the 2 satellites in my MR60 Nighthawk Mesh were off-line.  The normally blue status light on the front was suddenly amber on both satellites.  I tried pulling the power plug on one for 5 seconds, but no effect. The light flashes white for a few seconds before becoming amber.  Next step was to remove power to my cable modem and remove power from the Nighthawk base router unit, but after both were powered-back up and on-line, the satellites both remain amber.  I looked for firmware updates, and it appears I was able to download one, but it fails to do anything (fails to install).  I was hoping to call or chat with Netgear Tech Support, but have not been able to find a phone number or chat box.

Hi C541 and they_lion,

Good day!

Thank you for reaching out. We are sorry to hear about your experience with the device. Your devices are Mesh routers, not extenders. Please post your concerns on this link:

https://community.netgear.com/t5/Nighthawk-Routers/bd-p/insider-nighthawk 

Please do not hesitate to let me know if you need further assistance. 

Regards,

Oliver

Community Team