https://download.mikrotik.com/routeros/6.45.1/routeros-arm-6.45.1.npk
Thx Timur, you are the best
This is honestly unacceptable! If you can’t fix your product, issue a recall! More than half a year has passed already..
These units are not cheap at all (230+ EUR) to purchase, and they can’t even perform their basic as-advertised functionality in a reliable fashion, for Pete’s sake!
Also..
Literally no one:
MikroTik:
Offers supposed WiFi stability upgrade; SFP+ port no longer works
i suppose that nobody tried another OS on rb4011…
test on 6.46beta16, wlan1 disabling itself. not fix
Hello, Frostbyte, I have the exact same situation, 7 months. No response and no response that the device is defective. The only thing that I received from the support is that they have been working on the problem for 7 months already. This is sad!
They write that they fixed 802.11ac for ARM, but in the end it was frustrating.
In my regions, all distributors - seeing my problem do not order the RB4011, for fear of return and complaints. And this is all that I could achieve.
i still believe that it’s a hardware version problem; i haven’t this problem with wlan1 disabling itself (router bought from romania, in december 2018).
for sure, 160mhz option isn’t working, even if the settings say so; and only once wlan1 started to search another free 5ghz channel, due of meteo radars relatively nearby [an anti-hail rockets system at ~10km], kicking me out for those regulated 10 minutes.
I also bought the RB4011 in 2018, in December. After the MUM, fell for advertising.
Came to me in early January. And there is a problem.
PCI info of RB4011 - Atheros Communications Inc. unknown device (rev: 0)
Most likely the problem is in the wifi chip, it is previously a revision. According to the openwrt people Atheros QCA9984 rev 1.0, and the problem was solved by the firmware of the chip back in 2018. I am very disappointed in RB4011. I do not want to be more impressed. 
@mikrotik seems to me not looking there at all. Constantly write increased stability in 802.11ac. wlan1 often crashes when a device reconnects to RB4011 from another device.
And there will be ipv6 - multicast.
and here are the links to fixes on openwrt on the QCA9984 chip:
https://patchwork.kernel.org/patch/10723033/
https://patchwork.kernel.org/patch/10385043/
after a wlan1 failure, a red diode is lit on the inside of the device.
I found a solution!
i hade wlan1 was always in the bridge. If wlan1 is removed from the bridge, then it stops falling, and the red diode goes out.
In the case of CAPSMAN, I installed a datapach for wlan1 without Local Forwarding, and it also stopped falling, and the red diode is off.
@mikrotik, why should an expensive router users themselves look for your problem? We have been talking about the problem for 7 months already, and you are silent - like a fish on the ice! You have a problem with ROS in the bridge for QCA9984!
The problem is with ipv6 multicast or with bridge on 5ghz?
something makes wlan1 fall, obviously not the correct processing of data from wlan1. If refer to patches from openwrt then multicast.
As i wrote before. On my hap ac2 with the caps manager and without local forward on the wifi its running fine. Maybe this helps someone
Yes, only link performance drops
160mg is for future, if people try or complain about an iphone not connecting at that speed.. the istuff don’t support it. The ac norm is not made to be all time on, it’s an hashing power. Better to used the 10g fiber port or simple eth cable to have a full conectivity. Why wifi is so needed ? Only a battery operated stuff need it, the rest, as soon you need to be plug to the ac, you can have an eth cable.
Do a netinstall, do the simple ac setup /corner left and all is up and wifi work without disconnect. So no vlan, no ipv6, no extra firewall stuff… This is the basic first step to do before saying it’s not working. and not after a-b-c-z mod and addition of vlan and multiple subnet and so on..
Cutting off multicast completely is probably a terrible idea since many applications rely on that (AirPlay, Dropbox just to name two).
Also, phones are pretty capable of ac but they rarely use it due to the battery consumption.
Tablets and laptops in the other hand… well, ac is needed.
I want to see how you drag Ethernet cable to a TV, thermostat, smart speaker and all different things which are wired to the power but connected to the WiFi for convenience. You cannot tell your customers that you will rip their walls and connect everything using an Ethernet cable… cmon, it’s 2019.
p.s. also the point about ipv6 is completely missed. A lot of systems use IPv6 in the local network. Disabling IPv6 nowadays is like refusing to use LTE.
how much can we do netinstall! Do you think idiots here?
if we do not use multicast, vlan, ipv6 and so on - then why is this neutered device needed?
Can take ASUS or Tp-Link for morons and everything works without tuning.
Synology RT2600ac - QCA9984, there were similar problems, even in 2018, and they solved them.
In the framework of this forum, I gave a link to the forum of theirs.
PS
Do you think I did not with an empty config and did not check?!. @Mikrotik has a ticket with suppot files and not one. And not only from me open tickets.
PS
Synology - they screwed WPA3 back in 2018, CARLL!
Synology RT2600ac Release Notes - v1.2-7742 (2018-10-16)
Added support for WPA3 Personal/Enterprise
PS
on the other hand, they release 6.45.2 and send an SPF port to hells. A week has passed and no warning in the description of a stable branch, and if it were not for the forum, many would suffer.
Sorry but i cant verify.
I removed wlan1 (5ghz) from bridge but still dose not work.
I tried disable/enable but… same problem.
I tried add to bridge again but… nothing.
I tried all combinations with above (without restart) but nothing worked.
5ghz work only after reboot and for limited time.