Door/window sensor become unavailable

I’m using HomeAssistant Core 2024.3.3, OS 12.1. I am using ZHA and not ZigBee2MQQ. I use this ZigBee-Stick: EZSP by Silicon Labs, Firmware: 6.10.3.0 build 297. I use 27 ZigBee devices.
I’m having some problems with the following device: TS0203, TZ3000_6zvw8ham. It is a door/window sensor.

Yes, I have already tried to solve this problem by repairing or deleting and re-adding this device.

When I open and close the window, Home Assistant detects it. The main problem is that I control a thermostat through this sensor in conjunction with a second sensor (_TZ3000_9zt9jcbd).

Here are some Debugging Informations:

Zigbee info
IEEE: a4:c1:38:d6:11:60:0b:48
Nwk: 0xbfbb
Device Type: EndDevice
LQI: 200
RSSI: -50
Last seen: 2024-03-27T13:47:38
Power source: Battery or Unknown

Logbook:
K-F2 Öffnet was closed
1:47:38 PM - 7 minutes ago
K-F2 Identifizieren became unknown
1:47:32 PM - 8 minutes ago
K-F2 Firmware became unknown
1:47:32 PM - 8 minutes ago
K-F2 Attribute Updated event was fired
1:47:32 PM - 8 minutes ago
K-F2 Öffnet was closed
1:47:32 PM - 8 minutes ago
K-F2 Öffnet was opened
1:47:32 PM - 8 minutes ago
K-F2 Identifizieren became unavailable
12:42:41 PM - 1 hour ago
K-F2 Firmware became unavailable
12:42:41 PM - 1 hour ago
K-F2 Öffnet became unavailable
12:42:41 PM - 1 hour ago
K-F2 Öffnet became unavailable
12:42:41 PM - 1 hour ago
K-F2 Zha Event was fired
12:42:41 PM - 1 hour ago
K-F2 Öffnet was closed
6:39:26 AM - 7 hours ago
K-F2 Identifizieren became unknown
6:39:24 AM - 7 hours ago
K-F2 Firmware became unknown
6:39:24 AM - 7 hours ago
K-F2 Attribute Updated event was fired
6:39:24 AM - 7 hours ago
K-F2 Öffnet was closed
6:39:24 AM - 7 hours ago
K-F2 Öffnet was opened
6:39:23 AM - 7 hours ago

How is the distribution of your Z-Wave devices? It could simply be that the nearest device is just too far away to be a reliably path back to the dongle. Bear in mind that not all devices are created the same, those little sensors have smaller antennas so they should be in a room with a very nearby MAINS device to talk to - and ideally a couple.