[ZHA] Zigbee integration slows internet in whole network almost to zero

Hello. I am actualy building network of zigbee sensors.
I have connected Zigbee adapter SONOFF ZigBee 3.0 https://sonoff.tech/product/diy-smart-switch/sonoff-zigbee-dongle-plus-efr32mg21/ and one sonoff door sensors is connected via zigbee.
This works as expected.

Home assistant is running in container on RPI3.

And when I activate the zigbee integration, the internet speed slows down for a whole network almost to zero. (from 150 Mb/s to aprox. 1 Mb/s)

When the integration is stoped. The internet immediately returns to full speed.

Did anyone encountered anything like this?


How do you test the internet?
A cable directly to the router with the internet connection?

I measured speed by various tools (speedtest-cli, speed tests in browser…) and the results are consistently low. (And the internet is slow objectively. Loading of any page is visibly slower)

Everything is connected via ethernet cable directly connected to router.

Ok, then it is probably not a saturated frequency band.
Try to look at what log options you have on the router.
You need to figure out more about the slowdown, like what packet types, IPs, ports and so on that the router is busy with.