So far I have only done two prints and I only managed to get the GF online by rebooting my router with the GF still on. The GF still gets the same local IP address as lease is set to 1 day. The router is an Asus RT-AC66U running the latest firmware. The logs show that it usually connects with 3 or 4 attempts left but then they show that it seems to disconnect:
2018-04-04_15:49:25.42415 899730 INFO: WebSocketClient: connection established
2018-04-04_15:49:25.43797 899733 INFO: net: connected
2018-04-04_15:49:25.43803 899734 DEBUG: net: websocket interface has address 192.168.0.126
2018-04-04_15:49:25.86648 900172 INFO: WebSocketClient: connection closed
2018-04-04_15:49:25.88255 900176 INFO: net: disconnected
2018-04-04_15:49:25.88260 900176 WARNING: canceling transfer https://app.glowforge.com/api/machines/status
2018-04-04_15:49:25.88262 900176 ERROR: update machine status: url=https://app.glowforge.com/api/machines/status http_code=0, result=42 (Operation was aborted by an application callback)
2018-04-04_15:49:28.87095 903174 INFO: net: requesting socket token
2018-04-04_15:49:31.56186 905868 INFO: socket token request: http_code=200, result=0 (OK)
This might be a wireless module firmware issue.
They are currently using version 8.9.0.0.76 of the wl18xx firmware. It apparently has a bug that is causing the firmware to randomly core dump. I’m seeing the same problem on my development board (I use a different TI module, but the same firmware. It’s been a thorn in my side, as it is very intermittent.).
TI has apparently resolved the problem in the latest release, though I haven’t had a chance to test it myself:
http://e2e.ti.com/support/wireless_connectivity/wilink_wifi_bluetooth/f/307/p/675405/2494361
If this same issue is affecting the Glowforge factory board (and I assume it to be likely), a simple firmware update from GF should be able to fix it.
EDIT: Looks like the wireless module firmware was updated from 8.9.0.0.69 to 8.9.0.0.76 in Glowforge firmware v1.3.2-16 released on Feb 26, 2018. This was probably done to address the WPA2 vulnerability.
Well I haven’t changed anything, but was able to start up the GF today with no issues at all. Hopefully it will continue.
Have you ever looked in to whether the Glowforge is pingable, and if that changes with how cranky it is being?
I haven’t yet had a problem with a mysterious offline condition, but when I inevitably do I will find the standard voodoo techniques to be dissatisfying. 
I assumed it is because it is a Linux device. I think I can ping every device on my home network. Even the ones I programmed the IP stack myself. I actually coded the ping handler.
It could be disabled but why would you? It’s a standard network diagnostic.
I don’t think it would affect it being cranky but it does show whether it is connected to your router and is still responding.
Since this appears resolved, please open a new post if you have a new question. thanks!