Failed to deliver message: <EmberStatus.DELIVERY_FAILED: 102>

Configuration Zigbee
64

Usage on all your channels seems very high (the second number is a percentage). Here’s mine. ZHA is on channel 20, Z2M on 15:

"energy_scan": {
      "11": 80.38447947821754,
      "12": 84.164247274957,
      "13": 88.70042934643088,
      "14": 65.26028270288712,
      "15": 31.01324838787301,
      "16": 4.15070068297423,
      "17": 12.244260188723507,
      "18": 12.244260188723507,
      "19": 70.89933442360993,
      "20": 59.15797905332195,
      "21": 6.011489450827149,
      "22": 6.011489450827149,
      "23": 8.631361812931262,
      "24": 6.011489450827149,
      "25": 1.1664179210724432,
      "26": 62.257682586134884

This may indicate interference. I see you are using a USB extension cable - is it the one that came with SkyConnect? I replaced that with a 2m one. What wi-fi channels are your neighbours using? If they have their router on auto it may change from time to time.

I’ve noticed no difference after recent updates.

Edit: And I know this is a bit of a cracked record, but three routers is not going to get you very far. Zigbee doesn’t depend on signal strength (always weak); it needs many, many connections so that messages can take alternate routes. Here’s my map:

image
image1113×869 108 KB

Another edit: I expect you’ve looked at all the guides: