Hi,
I've done a dirty upgrade on a Asus RT-AC66U B1 router six and a half days ago from firmware 386.3_2 to 386.4_0 from a remote location using openvpn.
About five days ago I've done a dirty upgrade on my Asus RT-AC68U with HW ver. A1 router from 386.4_beta1 to 386.4_0 from the premises. I also used 386.4_alpha2 and both 386.4_alpha3s on this router, all dirty upgrades one after the other from 386.3_2. I didn't use the other betas because I was away from the router and didn't want to risk losing connection to it's lan by doing a remote update and when I got back, 386.4_0 was already released.
Just as a side note, when I updated to 386.4_alpha2, my SanDisk Ultra Flair 3.0 32GB flash drive, that I used for some scripts and swap, died. It served me a good 3 years and 2 moths and it still has until 5 years of warranty, but since it failed in the best way possible, by being set to read-only mode, I thought that for $7 (19% VAT included) I should just get another one and I did, but not before five days ago, when updating to 386.4_0.
Since I live alone now and have only a wired desktop and an iPhone 6 as a WiFi device, I didn't "catch" the 2.4 GHz WiFi problem, since the phone was connected to WiFi, on 5 GHz, and I didn't investigated on which frequency it was connecting.
I have no other WiFi equipment. Edit: Total brain fart on my part, I have a smart tv which has dual band WiFi 4, but which I don't keep connected to the network, I only use it via HDMI.
After reading through this thread and seeing the multiple reports on 2.4 GHz WiFi not working I decided to investigate and indeed it isn't working for me also (i.e. my iPhone 6 cannot connect to it). Strangely, my sister's Asus RT-AC661 B1, which I updated remotely and which uses the same firmware as my Asus RT-AC68U, doesn't seem to have this problem, at least not with the clients she's using, a Motorola mobile phone (don't know the exact model, E6 play or something like this) which only has 2.4 GHz WiFi and an old Toshiba laptop (with a Core2duo cpu) which I believe is only 2.4 GHz capable as well. Other phone and laptop are 5 GHz capable and should work at least on this frequency.
I tried many different thing, short of resetting my network setting on the iPhone (which may very well have solved the problems, but for not wanting to lose the various saved WiFi profiles I didn't do) and couldn't make the phone connect to 2.4 GHz WiFi. I've rebooted the phone and forgot the WiFi network, also used a different SSID and password on the router but to no avail, it doesn't connect.
On the router (always using 20 MHz, channel 1, WPA2-Personal and 3600 seconds group key rotation interval) besides the aforementioned different SSID and password, I've tried: Wireless Mode: Auto, Legacy and N-only; disable 11b option (which once enabled I could not disable, unchecking the box and hitting Apply button would result in the checkbox returning); Protected Management Frames: Disable, Capable (the setting that I'm using); Preamble type: Short and Long; DTIM interval: default of 3, tried 4, 50; Modulation scheme: MCS7 and MCS9; Airtime Fairness, Explicit Beamforming and Universal Beamforming: Enabled and Disabled.
I also tried cold booting the router, resetting the settings, formatting jffs and the usb flash drive (all further tests were done without the flash drive connected). I reset the settings both from WebUI and by holding WPS button from a cold start until power led started blinking.
After rebooting with all settings wiped, the phone would connect to the default, open "ASUS" ssid; but as soon as I changed it in the WebUI wizzard, so just a different ssid and with a password, it would no longer work.
Tried older firmware 386.3_2 and 386.2_4 (just to see the wireless drivers) and both worked.
I also tried the two latest stock firmwares, version 3.0.0.4.386.45934 from 2021-11-16 and version 3.0.0.4.386.45987 from 2021-12-16, WPS resetting every time, also cold booting. The former, 386.45934, exhibits the same behavior as 386.4_0, which is the iPhone could not connect, while with the latter, 386.45987, the iPhone can connect once again.
I've downgraded my Asus RT-AC68U to 386.3_2, restored the setting, restored jffs partition, plugged in the usb flash drive, rebooted and waiting on the next alpha once RMerlin receives an updated gpl from Asus and has time to merge it and compile it.
Edit: I've upgraded to 386.4_0 again to test using the smart tv and the phone and long story short now I can reliably connect both the tv and the iPhone to the 2.4 GHz WiFi as long as Disable 11b is not checked. If I check it and hit Apply, I cannot uncheck it from WebUI, as I previously said, but it can be done from the terminal:
Code:
nvram set wl_rateset=default
nvram set wl0_rateset=default
nvram commit
service restart_wireless
With Disable 11b checked, the two nvram variables are set to ofdm; I checked the Asus RT-AC66U B1 and it has the two variables set to default.
I don't know how my earlier tests failed since after a reset these variables are set to default, but nevertheless they did.
These are the settings I use now for 2.4 GHz:
View attachment 38459
View attachment 38461
Edit 2: I'll make a new post and link it here once it's done.
Thank you RMerlin for your efforts!