Network unstable after upgrading to 25.12.4

I'm suffering from network instability since I upgraded to 25.12.4

I have 1 router- Zyxel EX5601-T0 ubootmod
and 2 AP's - TP-Link Deco M4R v1

I expect the issue to be in the Deco's,

Wifi is instable near the Deco's,
sometimes there are no issues, but then suddenly all network traffic, both internal and external die.
the wifi symbol then still tells me the signal is strong.

Not sure if the issue is with 5Ghz, or 2.4Ghz

I can't see much in the log, is there something I could do?
Or should I replace my AP's?

Check the ethtool workarounds posted on the T-56 wiki page, could be related.

Does internal traffic pass the 5601, if it doesn't, it's not related to the 5601.

If you bypass the Decos, and connect to the 5601's wifi, is it stable?

thnx,
I modified the file

```
root@OpenWrt:~# nano /etc/rc.local
root@OpenWrt:~# cat /etc/rc.local
# Put your custom commands here that should be executed once
# the system init finished. By default this file does nothing.

#Hotfix stability issues (TO be removed some day) see: https://openwrt.org/toh/zyxel/t-56
ethtool -s wan advertise 0x028
ethtool -s wan speed 1000 duplex full autoneg on

ethtool -s lan1 advertise 0x028
ethtool -s lan1 speed 1000 duplex full autoneg on
#End hotfix
exit 0
root@OpenWrt:~# ethtool -s wan advertise 0x028
root@OpenWrt:~# ethtool -s wan speed 1000 duplex full autoneg on
root@OpenWrt:~#
root@OpenWrt:~# ethtool -s lan1 advertise 0x028
root@OpenWrt:~# ethtool -s lan1 speed 1000 duplex full autoneg on
root@OpenWrt:~#

```

now both are running static on 1Gbps (I suppose)

Does internal traffic pass the 5601, if it doesn't, it's not related to the 5601.

it does for DNS routing. (udp causes less issues then tcp)

If you bypass the Decos, and connect to the 5601's wifi, is it stable?

there are no issues for devices directly connected to the T-56

I will monitor if the stability is improved,

now the only thing is to not forget about this file when I replace my AP's or a fix will be provided.

Unfortunately,
still one instance occurs where the WiFi on the deco died, (it recoverd in a few minutes)

I rebooted everything, but I think maybe I'm just at the limit of the 128MB RAM, while the AP is heavily used

[edit]:

The device on the lan interface never has issues, and checking the log, the issues seems to occur on the 5Ghz channel only (Qualcomm Atheros QCA9886 802.11ac/n),
So for now I disabled the 5Ghz on my deco's

update from my side,

I enabled 5Ghz again using the ct driver

apk del kmod-ath10k ath10k-firmware-qca9888
apk add kmod-ath10k-ct ath10k-firmware-qca9888-ct-full-htt
reboot

And at first attempt the thing where the old driver crashed, it doesn't crash now.