Some lights in light group stop listening when quickly sending commands

[YAMLcase]

I’m working on tweaking performance and have this annoyance I can’t seems to find root cause. Symptom is toggling on/off the zigbee group quickly. The lights respond instantaneously the first few toggles, then 1-2 lights stop listening for another toggle, then they all stop listening until I stop toggling for few seconds. After this wait, they respond instantaneously again. During the time the commands seem “clogged”, I can still send and receive other zigbee messages. i.e. I press buttons on a remote I have paired and see MQTT messages fly by.

I’ve messed with the following things that either had no effect or degraded performance somehow:

• setup a home assistant group and toggled that instead
• configured these various settings in z2m:
  • concurrency: 2, 16, 100
  • adapter delay: all the way up to 2000
  • QOS 0, 1, 2
  • retain settings on the lights
  • optimistic
    I feel like I’ve tried all I know to try, so any suggestions?

My setup:

• 4 Sylvania Ledvance color/white downlights in a zigbee2mqtt group
• each component in a separate container, latest or stable version pulled today:
  • z2m
  • mosquitto
  • home assistant
• Tube’s CC2652P2 ethernet coordinator, layer-2 adjacent on same switch as docker server
• using channel 25, no other signals at this frequency. nearest 2 wifi are on channels 1 and 6. I live out in the country so 100% sure about no wifi on channel 11.