Here’s the current community guide that covers zigbee. If you scroll down a bit to the common issues, you’ll see mentions of specific hardware combos that cause issues intermittently.
Issue: Poor placement of the Zigbee adapter or wrong orientation of the Zigbee adapter antenna
Issue: USB 3.0 ports/computers/peripherals are known culprits of RFI/EMI/EMF disruption.
Raspberry pi4’s have 2 usb 3.0 ports which are known to cause interference.