RT-AX86U - Wifi slows down randomly to 3-5 Mbps

[Sanek2k6]

I'm running RT-AX86U Firmware 3.0.0.4.384_9318 on mostly default settings and advanced features are not being used. For some reason, one second 5GHz Wifi may be 500 Mbps+ for a device and within a few minutes it could drop down to just 3-5 Mbps for it. After disconnecting and reconnecting the client, everything is normal again, but only for a few minutes. Most obvious is the wifi connection for my iPhone Xs Max that seems to exhibit this behavior.

I played around with disabling beamforming and that didnt seem to help. Also tried moving the device to some unutilized channels (CH56 - current, CH104, DFS) and it seemed to work stable for a few days, but would always go back to this issue. I am in a fairly busy Wifi area, but I can see which channels are being used, so I did select the ones not being utilized at all.

- IPV6 is enabled.
- UPNP is disabled.

Does anyone have any similar issues? This has been driving me crazy...

 

[Morpheus2020]

In 384.9318 of AX86U, I know a bug which causes the upload speed of 5G wifi only 3-5M.
If you switch any features of Trend Micro On , your syslog will be full of "kernel: invalid dirty_p detected: ffffffc000000000",and your upload speed of 5G wifi will very low.
You can see if there are similar entries in syslog.

 

[Sanek2k6]

In 384.9318 of AX86U, I know a bug which causes the upload speed of 5G wifi only 3-5M.
If you switch any features of Trend Micro On , your syslog will be full of "kernel: invalid dirty_p detected: ffffffc000000000",and your upload speed of 5G wifi will very low.
You can see if there are similar entries in syslog.

I don’t use any of those features - all that stuff is disabled. I don’t really see any errors in the log either, just a log for client disconnect (I believe) and some upnp denied logs, even though upnp should be disabled

 

[tallytr]

I've only ever used channel 36 on 5GHz and that works beautifully also with my RT-AX86U...
Use free Wifi Analyzer from Microsoft to scan your environment?

 

[Sanek2k6]

I've only ever used channel 36 on 5GHz and that works beautifully also with my RT-AX86U...
Use free Wifi Analyzer from Microsoft to scan your environment?

I did scan my environment - see the screenshot in first post. Channel 36 has 5 devices on it already and is the busiest 5G channel

 

[tallytr]

I did scan my environment - see the screenshot in first post. Channel 36 has 5 devices on it already and is the busiest 5G channel

Don’t think the # means much, signal strength matters, these may be far away?
You will figure it out, it’s a great router for sure, if nothing helps and your clients are not stable I’d factory reset...

 

[L&LD]

What matters is what those other AP's are doing (throughput). If you happen to be close to many, but they are not utilized fully, and their signal strength at your router is good or better, they are effectively not there.

(The signal strength matters because if your router can't 'sync' with the other AP's, nothing transmits until they can).

 

[Sanek2k6]

Well I was placing it on unused channels either way and I’ve still been having this issue, so doesn’t look like it has to do with that anyways

 

[Batnun]

In 384.9318 of AX86U, I know a bug which causes the upload speed of 5G wifi only 3-5M.
If you switch any features of Trend Micro On , your syslog will be full of "kernel: invalid dirty_p detected: ffffffc000000000",and your upload speed of 5G wifi will very low.
You can see if there are similar entries in syslog.

Never heard about this bug... Everything is working great with my RT-AX86U, with the latest office firmware, and I'm getting connection speed between 700-800 Mb/s...

 

[KevTech]

Do not have this issue and all setting stock except for channel is now fixed and roaming assistant is disabled.
What I do for channel is place it on auto then see what channel the router sets then use that channel as a fixed channel.