A bright thought just came to me.
At the moment, the firmware for AX4200 and AX6000 (not AX59U) has a defect that causes a soft brick if the image size is more than 16MiB.
I discovered this defect a long time ago and immediately fixed it in my builds.
But today I checked branch openwrt-23.05 and no one made any corrections there.
I immediately informed the maintainers about this problem:
I installed 23.05.3 without a problem, I used remittor's trx first on stock, then flashed the 23.05.3 stable build. Been running good for couple days now, but maybe I got lucky? I tried getting QoS SQM setup but gave up after seeing poor performance and just opted to turn on software/hardware offloading and it runs well. I got unbound installed and working for secure DNS, and setup a wireguard server over ipv6 since tmobile home internet has cgnat on ipv4. I'm happy.
Status
System
Hostname OpenWrt
Model ASUS TUF-AX4200
Architecture ARMv8 Processor rev 4
Target Platform mediatek/filogic
Firmware Version OpenWrt 23.05.3 r23809-234f1a2efa / LuCI openwrt-23.05 branch git-24.073.29889-cd7e519
Kernel Version 5.15.150
Local Time 2024-03-26 20:14:57
Uptime 23h 37m 47s
Load Average 0.26, 0.18, 0.13
Since the AX6000 has received official support since OpenWrt 23.05.3, I would like to ask whether there are other installation options besides
Official: Serial Console
Unofficial: from remittor (Asus TUF Gaming AX6000 support - #151 by remittor)
I forgot to update that I got piece_of_cake working and somehow Bufferbloat test by Waveform.com started to work stable even if I was able to verify the connection by stressing the connection and pinging in the same time. I activated SQM only in UL because DL is +3 ms when the connection is loaded and simultaneous DL/UL was quite heavy process which caused decreased DL speed. I already had packet steering enabled but I just installed and enabled irqbalance with it. Bufferbloat and Internet Speed Test - Waveform
The ONT is Nokia XS-010X-Q and I assume it's bridged but not sure because the operator controls it.