YA channel utilization thread?

In general, my zigbee network works alright. But recently I’ve noticed some devices having trouble. I reconnected some of them and they’ve stayed connected, but a few others disconnected again.

I have these messages in logs:

Zigbee channel 11 utilization is 89.94%!
If you are having problems joining new devices, are missing sensor updates, or have issues keeping devices joined, ensure your coordinator is away from interference sources such as USB 3.0 devices, SSDs, WiFi routers, etc.
Zigbee channel 11 utilization is 87.33%!

I have the SkyConnect.
I have a few Ikea repeaters throughout the house (and also a few Sonoff S31zbs).
I have neighbors, but they are not close by (nearest is probably 250-300ft or so from any of my devices).
I have my WiFi APs (for 2.4ghz) on channels 6 and 11 only so I have no nearby direct interference from the wifi.

I downloaded the diagnostics file and found:

    "energy_scan": {
      "11": 43.057636198227904,
      "12": 70.89933442360993,
      "13": 55.9836862725909,
      "14": 46.26944564832987,
      "15": 99.84693026606404,
      "16": 43.057636198227904,
      "17": 59.15797905332195,
      "18": 59.15797905332195,
      "19": 65.26028270288712,
      "20": 28.30261646762903,
      "21": 73.50699819621309,
      "22": 85.82097888710312,
      "23": 92.95959997754716,
      "24": 70.89933442360993,
      "25": 62.257682586134884,
      "26": 99.77408388719513
}

Interference on channel 11 must spike or something if the logs are showing those 87%+ numbers?

Channel 20 looks promising here, but this is just one data point and logically, with 2.4Ghz wifi on channels 6 and 11, there is a lot of chance for adjacent channel interference there, so I think it would be risky to move to that.