First thing to try is to turn off the machine and log out of the app, especially if you have it open on more than one device.
While the machine is turned off, clean the lid camera with a Zeiss wipe.
Then turn the machine back on and let it completely finish the startup calibrations and the head return to the home position in the upper lefthand corner before you log back into the app.
If it’s still stuck, you can try rebooting the router, and computer, clear the cache, and if all else fails, reset the Wifi connection. You might have to move the router closer to the Glowforge, or establish a stronger signal some way…when it gets hung up calibrating I believe it is usually a sketchy Wifi signal.
Instructions from the Troubleshooting section on it are here:
1. Restart all the devices
Turn off the computer, phone, or tablet that you’re using
Turn off your Glowforge
Unplug your modem
Unplug your Wi-Fi access point
Wait one minute, then plug everything back in and turn them back on
2. Improve the signal path between your Glowforge and your Wi-Fi access point
Wi-Fi signals need a clear path. Remove physical barriers, and move devices closer together:
Move your Wi-Fi access point up high and make sure it’s in an open space. Avoid locating your Wi-Fi access point on the ground, under a desk, in a cabinet, or in a corner where its signal can be blocked.
Relocate your Wi-Fi access point closer to your Glowforge
Move your Glowforge closer to your Wi-Fi access point
Install a Wi-Fi range extender closer to your Glowforge
Run an ethernet cable and install a second Wi-Fi access point next to your Glowforge
3. Reduce electronic and Wi-Fi interference
If your unit is near other devices that use Wi-Fi or a large number of electronics, temporarily turn off other electronics and devices in the area.