RT-AX88U - Very slow DL speeds, running 38.14; Modem known good

[gcbspender]

HI,

Having a frustrating issue I can't nail down. Last night I started getting incredibly slow DL speeds and some jitter. I have had my AX88U for about 3 weeks now and was still running stock firmware. Everything was fine til last night, router said it had a firmware update. Ok, so I updated as I figured that might fix something. That was after a few restarts of the modem and AX88U. So I upgraded to latest Stock Firmware. NO dice, same results. I am getting >9 mbps Down. Upload speeds are almost normal but I only get about 10-11 anyways. Now when I plug in the Modem directly to the computer I get what I should 240 mbps down.

I have hard rebooted all equipment several times. Still no change. So I installed Merlin 38.14 thinking there must be something wrong with the new stock firmware. Everything installed great and my settings applied just fine. But unfortunately, same results, less than 9 megs down. I am not seeing anything obvious that would be gumming up the works.

Under Home> WAN, the Asus did report a couple times that the DHCP of the ISP was not being divvied out. After turning WAN off and then On it was fine. Also to note, When I try to log into the Modem directly to it's IP address I get security warnings within the browser, saying the site is not safe or private and I can't reach it even after I click the link that was go to website. I have turned Firewall off on Asus and tried again, same issue.

Again, several hard restarts and changed all cables in the run. Any ideas? Do I have a lemon router?

Thanks for any help!

 

[L&LD]

After flashing RMerlin firmware on the router, did you do a full reset to factory defaults and then configure the router minimally and manually to connect to your ISP and secure the router?

See the M&M Config in my signature below for further instructions.

 

[gcbspender]

After flashing RMerlin firmware on the router, did you do a full reset to factory defaults and then configure the router minimally and manually to connect to your ISP and secure the router?

See the M&M Config in my signature below for further instructions.

No, I just flashed and then re-applied settings that were in place. Which really isn't that much. Only 5Ghz wifi, some port forwarding. But the problem also existed before the Flash of Merlin. No changes were made to settings between the time I initially set it up 3 weeks ago to last night with the stock firmware. Just suddenly stopped outputting high download speeds.

 

[L&LD]

How did you reapply settings? Did you use a previously saved backup config file?

Is so, that is most likely the cause of your issues. You need to reset the router when flashing between stock and RMerlin firmware.

I would suggest following the M&M Config guide to put your router back to a good/known state.

 

[gcbspender]

Ok, so based on these suggestions. I started stripping away settings. Once I turned off QoS my speeds jumped up to where they should be. Why has the QoS suddenly killed my download speeds across the board? No matter what I tested, hardwired or Wifi devices I had horrible DL speeds.

 

[S.claus]

Make sure your manual download/upload values are correct (maybe you typed your upload into the download and vice versa) . Leave WAN overhead on 0 and use fq_codel

 

[gcbspender]

Weird. Turned adaptive Qos back on but this time set bandwidth setting to Auto. Speeds remained good. Thanks for all the help!

 

[gcbspender]

Make sure your manual download/upload values are correct (maybe you typed your upload into the download and vice versa) . Leave WAN overhead on 0 and use fq_codel

I did check that first and they looked good to me. But as you see above turning it to Auto fixed the issue so maybe it was corrupted in the settings somehow and limiting it much lower than what it should have.