By “pulsing” do you mean the light is scanning back & forth like the light on the K.I.T.T. car from the Knight Rider tv show? That’s what mine’s been doing. I don’t think it’s a connection issue though since I’m still able to watch stuff on it.
I am also facing same issue. My cube starts working if you do power reset so I was bit lazy calling support. but finally I called today. I faced this issue couple of days back and my Fire TV cube is working fine so they couldn't get any logs. They have requested to call back when the issue comes or even a day later if we call then also they should be able to get the logs (like if you are watching a movie and don't get stuck due to this).
Seems the support also is open 24/7 so that helps. I am going to call next time, may be you should also give a try if you are facing this issue.
Though I learnt a new thing, they told rather than going to power outlet and removing the plug and putting it back if we simply press PLAY + ROUND Button and keep it pressed for sometime it will restart the FireTV cube.
My Fire TV cube frequently displays the orange sweeping light. When it does streaming TV works from Fire TV Recast fine but Alexa doesn’t have this issue. Going to Settings > Networt shows a strong Wi-Fi signal. Pressing the play/pause key to run the troubleshooter clears the light, shows a strong signal and Alexa works for a few minutes before the sweeping amber light returns when using Recast and Alexa becomes unresponsive. My setup is an LG TV and Visio 5.1 sound bar daisy chained on HDMI and using CEC for control. I have the Fire TV remote with the volume on it. Fire OS version 220.127.116.11(NS6258/160.. and Fire TV Home Version 18.104.22.168-267. I hope Amazon will fix this annoying problem soon!
I've been seeing this on mine also. I never noticed Alexa not working since I don't use the voice control, just the remote. Definitely sounds like some sort of glitch in something. Hopefully they'll push an update to fix the issue.
I'm sorry you're experiencing this issue with your Cube! If you haven't already, check for Cube updates, restart both your Cube and router by unplugging them for a minute, start up your router first and once that is booted up, plug in the Cube. I'd also recommend checking for updates for your router. If you're using an Ethernet cable, unplug it and plug it back in to make sure the connection is good. If you have a dualband router, try connecting the device to either 2.4 or 5 GHz, whichever one it's not on currently.
I get the moving orange light only when I use my VPN (Private Internet Access). It goes out when I stop using the VPN. My Cube is Ethernet hard wired to my Netgear Orbi Router. I guess it is telling me there is something abnormal with the internet when I use the VPN.