Sengled Devices No Longer Responding

I have a mix of Samsung Smart Things Sensors and outlets, a Wemo outlet, a TP-Link bulb, and a bunch of Sengled bulbs.

The Sengled bulbs and the Smart Things Sensors use ZigBee, while the Wemo and TP-Link use WiFi.

Today, I noticed that all of my Sengled bulbs stopped responding. I’ve tried rebooting the RPi, factory resetting the bulbs, and so on. I know that the ZigBee network is intact because I’m still receiving data from the Smartthings sensors.

The Things Gateway seems to “see” the bulbs, as it doesn’t show a disconnected status, however, trying to toggle the bulbs on or off results in it getting stuck.

Repairing the bulbs doesn’t work. The RPi can’t even see it when I reset the bulbs to pair them.

I looked in the logs just now, and noticed an error message popping up:

zigbee: Confirm Status: 208: ROUTE_DISCOVERY_FAILED

I’m not sure where to go with troubleshooting from here. Are there any pointers or anything? Anyone else struggling with the same issue?

I’ve done some more testing, and I still don’t have the solution. Once it works, it works perfectly until the Raspberry Pi is restarted or the Zigbee adapter is reset. (It seems that it’ll work if I set it sit for a few hours untouched?)

If it’s crashed, I can restart the Zigbee adapter, and it’ll work fine for about 30 seconds, but then stop communicating with the Sengled bulbs suddenly. There’s no log entry except that the path to the device failed about 10 seconds later.