Hi, let me reiterate. I recently described how connections are restored:
In your case, by re-adding the Zigbee sensors (using the “+” button), you changed their routing path. It is possible that they have switched to a path where the signal is weaker than it was before. Also, keep in mind that all devices with a neutral wire act as Zigbee repeaters; turning off such a device will cause the Zigbee connection to break.