I've seen this happen a few times. Most likely the Echo Show will need a reboot. Just unplug it for a few seconds and plug it back in. The 2nd most common issue is a marginal WiFi connection, or it could be the internet connection to your ISP. Run a speed test from your computer or phone and see if you get slow ping reply times or lost packets. Also try moving your Echo Show to another location, preferably closer to your WiFi router.