Was that to a USB 2.0 port or did you use a USB 2.0 extension cable?
What else you can try is to first remove a few Zigbee End Devices and then add a few more Zigbee Router devices before add back any Zigbee Router devices. Buy some known good Zigbee Router devices or make a known great DIY Zigbee Router devices by flashing extra Zigbee USB dongles. All as per the guide.
But devices stuck on interviewing is usually (however not always) a sign of EMI interference so you should still also continue to take as many proactive measures for that as you can. Again as per the guide.