Zigbee Devices LQI Drops a Lot Over Small Distances

I have a handful of Tradfri bulbs and remotes, a range extender/repeater and an outlet. All paired to a V3 hub using the default DH.

My ST hub is on zigbee channel 14 and 2.4ghz WiFi is on channel 11. The hub is fairly far from the router, connected via 5Ghz Wifi.

The problem I’m having is that devices even 1m away don’t have a 255 LQI for the last hop (all in the same room as the hub). I’ve been monitoring it over the last few days and it’s kind of like this:
1m away ~210-240 LQI (bulb and remote)
2m away ~180-220 LQI (repeater/range extender)
4m away ~140-180 LQI (another bulb)
4m + ~100-160 LQI (a bulb in another room)

Mind you the 4m away bulb has the repeater right between it and the hub, and yet all devices in the room hop directly to the hub.

I’m getting occasional duplicate messages and failures reported in the IDE, and also one remote is super inconsistent when paired to the hub (I have it paired directly to the bulbs now so that it’s usable). This is the main reason I started looking at LQIs and noticed how bad they were.

Here are some other things I’ve tried or know:

  • The hub used to be ethernet wired to my router. Things were worse then in terms of LQI for the main devices I’m looking at since it was closer to the router and further from the devices.
  • The hub is turned sideways so that the zigbee radio faces the room and most of the devices.
  • The 2.4Ghz wifi around me has about 8 other networks present, with all of them having a strength of -80 (db?) or less, while mine is between -40 and -50.
  • There are no 2.4Ghz wifi devices in the room aside from my wife’s phone.
  • I’ve tried “healing” the zigbee network by disconnecting the hub for half an hour. There have also been two internet outages which forced that, and still all devices hop directly to the hub.
  • The house is wooden construction.