Zigbee devices (ZHA) became unresponsive

Since yesterday night a lot of my zigbee devices became unresponsive or very laggy.
I use ZHA with the Sonoff stick. Now today some devices are back online, some are not. I didn’t change anything since then.

I also use a long cable from the Raspberry Pi to the Sonoff stick.
I’m on the newest version

Core 2024.4.4
Supervisor 2024.04.0
Operating System 12.2
Frontend 20240404.2

Any ideas on how to troubleshoot?

Might be a power supply problem if you have anything else using USB ports on the PI (eg SSD). A powered USB hub would prevent that - has to be USB 2, though; USB 3 causes interference.

Otherwise, how many mains-powered devices have you got in the Zigbee mesh?