Zigbee2MQTT - Trained devices disappear after a short time

[sk-master02]

Hello dear community,

I started using Zigbee2MQTT about 2 weeks ago.
I use an SLZB-06M as a coordinator and two SLZB-06M as routers.
Now I have the problem that when I teach devices, they appear in the overview for a few seconds and then disappear again. (Message: Device 0xXXXXXXXXXX has left the network)
This happens with different manufacturers. (Sonoff, Tuja, Aqara)
Does anyone have an idea as to what this could be?
Sometimes the devices are then entered into the block list.

Zigbee2MQTT Version: 2.0.0-2
Number of devices in the network: 45
SLZB-06M:
Current core firmware version: v2.6.8.dev26
Zigbee: Your current firmware revision: 20241127

Zigbee2MQTT config:

data_path: /config/zigbee2mqtt socat: enabled: false master: pty,raw,echo=0,link=/tmp/ttyZ2M,mode=777 slave: tcp-listen:8485,keepalive,nodelay,reuseaddr,keepidle=1,keepintvl=1,keepcnt=5 options: "-d -d" log: false mqtt: {} serial: port: tcp://192.168.xxx.xxx:6638 baudrate: 115200 adapter: ember disable_led: false advanced: transmit_power: 20
Overview Network:

I hope someone can help me.

[sk-master02]

I found a hardware problem and fixed it. Question has been resolved

[adriaandotcom]

What was the hardware issue? Having the same issue with my setup: #25528

[sk-master02]

I had installed a different antenna on the coordinator.
This led to the problems.
Now with the original antenna everything works again.

[sk-master02]

problem solved