AP becoming slow on 5GHz when multiple clients connect

[beni_mahler]

Good afternoon,

I have noticed that my client shows between 10 and 40 Mbit/s in speedtest.net, but I am connected to a 5GHz SSID. I run 200.15.6.212.27 and the client is close enough to the AP. It is a Lenovo Win11 computer, "netsh wlan show interfaces" shows that i am well on the 5GHz Band, Signal is 75% and RSSI is -55. 

As soon as I disable the 5GHz on this AP and then re-enable it, my speedtest shows >200Mbit/s. The same happens if I block all 5G clients on this AP. Blocking 5G clients on the same ssid is not enough (I have four SSIDs running). Also the problem seems to be limited to this one AP. Upload alwas is a bit better than download and an upgrade to 200.18 didn't change the behaviour.

[Mayank]

Hi Beni_Mahler,

Thank you for posting your query.

My understanding of the issue is that one Access Point in your Ruckus Unleashed network consistently delivers very low client download speeds (10–40 Mbit/s) on the 5 GHz band despite good signal strength (RSSI around –55 dBm). The speed returns to normal (>200 Mbit/s) only after toggling the 5 GHz radio off and on. The issue persists across multiple firmware versions and affects only this specific AP.

Please correct me if I have misunderstood the issue.

I have one question — have you tried performing a factory reset on the affected AP? If not, could you please give it a try and check if the issue persists afterward?

Factory Reset Steps:

Please refer to the following video for guidance on unmounting and resetting the access point:

https://www.youtube.com/watch?v=vFD_ByQWGH0

Thank you,
Mayank

[beni_mahler]

Hello,

Your understanding is correct. I have not performed a factory reset, but I had the problem with a R350e before so I exchanged it with a R550 which was in the same installation but on another spot. The problem has persisted with the location but not with the AP.

In the meantime I also forced the AP to switch to another channel but without success. I could also factory reset if you think this could help.

[Mayank]

Hi beni_mahler

Please confirm the following points for us:

Is the issue only on the 5 GHz band, or do you also observe low speed on 2.4 GHz?

Have you tried connecting a laptop directly to the switch port or cable feeding this AP to confirm the wired speed?

How far are the clients from the AP when you test the throughput?

Was a site survey conducted prior to deployment?

Is the issue observed on specific APs, WLANs, or frequency bands (2.4 GHz / 5 GHz / both)?

Is the issue localized to a particular area or observed across the entire site?

Was the throughput ever normal at this location, or has it always been slow?

Are there any walls, metallic surfaces, or electronic devices (like cameras, cordless phones, or microwaves) near the affected AP?

Does the issue occur with all clients or only specific ones? (e.g., laptops vs. phones)

Thanks
Mayank

[beni_mahler]

Hi

I will test all of this in 2-3 days and then give a details answer. kind regards