Zigbee devices causing HA unreachable momentarily congesting z2m

What happened?

I have 124 devices in my zigbee network

Routers 74 lights 21 switch - all Aqara D1 1 Ikea repeater as router

Remaining are sensors

They are quite densely deployed in a space around 150m^2 (1600 sq ft.)

I have all switches configured in decoupled, whereas my lights are always on and digitally controlled. And I am running Nodered to handle switch actions, process their signals to render the lights to its best setting.

All zigbee devices are configured through zigbee2mqtt

In terms of responsive, they are okay, on average the lights will react within 2s after button event. What happens is while buttons are pressed, HA would occasionally become unreachable, during this time button action events are not processed, frontend will pause if I refresh the browser. While HA is unreachable, I was still able to ping HA by its IP. HA will become reachable again, queuing all the button action events in approximately 10s.

I am unsure if z2m is causing HA to freeze, as HA is only unreachable during z2m interactions with aqara button press.

Any idea how to proceed troubleshooting this issue?

Does this look like a familiar issue? I see version 20221226 has this change Improve performance/reliability for larger network (100+ devices), though it seems to be many-to-one changes. Not sure what's causing the hang, except it happens during button clicks.

Hoping to get some insights before upgrading the firmware

Please assist.

Home Assistant 2023.2.3 Supervisor 2023.01.1 Operating System 9.5 Frontend 20230202.0

What did you expect to happen?

z2m and HA works flawlessly.

How to reproduce it (minimal and precise)

pressing aqara d1 switch buttons
apparently z2m is congested, at the same time when HA becomes unreachable via browser but still able to ping

Zigbee2MQTT version

1.30.1-1

Adapter firmware version

20220219

Adapter

Sonoff ZBdongle-P, and another no brand from China, both CC2651P

Debug log

No response

Koenkk / zigbee2mqtt