Issue adding more than 4 thread devices with GL-S20 TBR

Configuration Matter/Thread
1

Maybe a similar issue than this but with another behaviour.

Here is my setup:
HAOS 2026.3.0
Matter Server App 8.2.2
OTBR, Thread, Matter Integration
Glinet GL-S20 with firmware V2.0.1-B1
Aqara devices (T2, FP300, Door and Window Sensor P2)

I have followed the guide from Glinet Work with Home Assistant - GL.iNet IoT Docs

The first 4 devices can be added without issue, when I try to add a fifth one, an issue arise at the step “Checking connectivity to Thread network”. I have a bunch of error on the GL-S20 logs during this process.
I’ve tried multiple joining order, it always fail at 5.

Here you can see my multiple tries from yesterday:

[2026-03-05 10:13:17] e[0;31mE (653231) OPENTHREAD: Failed to add servicee[0m
[2026-03-05 10:13:17] e[0;33mW(653231) OPENTHREAD:[W] SrpServer-----: Send fail response: 2e[0m
[2026-03-05 10:20:50] e[0;31mE (1106401) OPENTHREAD: Failed to add servicee[0m
[2026-03-05 10:20:50] e[0;33mW(1106401) OPENTHREAD:[W] SrpServer-----: Send fail response: 2e[0m
[2026-03-05 10:20:52] e[0;31mE (1108201) OPENTHREAD: Failed to add servicee[0m
[2026-03-05 10:20:52] e[0;33mW(1108211) OPENTHREAD:[W] SrpServer-----: Send fail response: 2e[0m
[2026-03-05 10:20:55] e[0;31mE (1111281) OPENTHREAD: Failed to add servicee[0m
[2026-03-05 10:20:55] e[0;33mW(1111281) OPENTHREAD:[W] SrpServer-----: Send fail response: 2e[0m
[2026-03-05 10:21:00] e[0;31mE (1116491) OPENTHREAD: Failed to add servicee[0m
[2026-03-05 10:21:00] e[0;33mW(1116501) OPENTHREAD:[W] SrpServer-----: Send fail response: 2e[0m
[2026-03-05 10:21:09] e[0;31mE (1125351) OPENTHREAD: Failed to add servicee[0m
[2026-03-05 10:21:09] e[0;33mW(1125351) OPENTHREAD:[W] SrpServer-----: Send fail response: 2e[0m
[2026-03-05 10:21:24] e[0;31mE (1140391) OPENTHREAD: Failed to add servicee[0m
[2026-03-05 10:21:24] e[0;33mW(1140391) OPENTHREAD:[W] SrpServer-----: Send fail response: 2e[0m
[2026-03-05 10:21:50] e[0;31mE (1165941) OPENTHREAD: Failed to add servicee[0m
[2026-03-05 10:21:50] e[0;33mW(1165941) OPENTHREAD:[W] SrpServer-----: Send fail response: 2e[0m
[2026-03-05 10:22:33] e[0;31mE (1209371) OPENTHREAD: Failed to add servicee[0m
[2026-03-05 10:22:33] e[0;33mW(1209381) OPENTHREAD:[W] SrpServer-----: Send fail response: 2e[0m
[2026-03-05 10:24:18] e[0;31mE (1314241) OPENTHREAD: Failed to add servicee[0m
[2026-03-05 10:24:18] e[0;33mW(1314241) OPENTHREAD:[W] SrpServer-----: Send fail response: 2e[0m
[2026-03-05 10:24:20] e[0;31mE (1316041) OPENTHREAD: Failed to add servicee[0m
[2026-03-05 10:24:20] e[0;33mW(1316041) OPENTHREAD:[W] SrpServer-----: Send fail response: 2e[0m
[2026-03-05 10:24:23] e[0;31mE (1319121) OPENTHREAD: Failed to add servicee[0m
[2026-03-05 10:24:23] e[0;33mW(1319121) OPENTHREAD:[W] SrpServer-----: Send fail response: 2e[0m
[2026-03-05 10:24:28] e[0;31mE (1324331) OPENTHREAD: Failed to add servicee[0m
[2026-03-05 10:24:28] e[0;33mW(1324331) OPENTHREAD:[W] SrpServer-----: Send fail response: 2e[0m
[2026-03-05 10:24:37] e[0;31mE (1333191) OPENTHREAD: Failed to add servicee[0m
[2026-03-05 10:24:37] e[0;33mW(1333191) OPENTHREAD:[W] SrpServer-----: Send fail response: 2e[0m
[2026-03-05 10:24:52] e[0;31mE (1348231) OPENTHREAD: Failed to add servicee[0m
[2026-03-05 10:24:52] e[0;33mW(1348241) OPENTHREAD:[W] SrpServer-----: Send fail response: 2e[0m
[2026-03-05 10:25:18] e[0;31mE (1373781) OPENTHREAD: Failed to add servicee[0m
[2026-03-05 10:25:18] e[0;33mW(1373781) OPENTHREAD:[W] SrpServer-----: Send fail response: 2e[0m
[2026-03-05 10:26:01] e[0;31mE (1417201) OPENTHREAD: Failed to add servicee[0m
[2026-03-05 10:26:01] e[0;33mW(1417201) OPENTHREAD:[W] SrpServer-----: Send fail response: 2e[0m
2

I don’t have a GL-S20 TBR, but during commissioning, the device is suppose to communicate with the SRP Server in the TBR and the SRP Server is suppose to send out mDNS advertisements over the LAN. From the logs, it appears that the SRP Server is not able to send out.

Just googling around, I came across the following (not sure it will solve your problem)

3

No success unfortunately, neither with 1.0.5 or 2.0.0 firmware