Altos CAP700: 2.4GHz download speed drops to ~1Mbps after 1-2 minutes, upload seems unaffected

Networking Solutions Issue
1

Current firmware information
Firmware version: CAP7_R_00.07.24.1
Firmware build date: 2026-07-16
Kernel version: 5.15.144-perf+
(I previously used firmware ver. CAP7_R_00.07.23.7 – same issue)

Problem: Download speed on the WiFi network is particularly slow when using the 2.4GHz network. Upload speed is higher.

Details:
Today I started using an Altos CAP700 router together with a 5G connection, which by itself works very well. On one laptop with WiFi 6, when I use the 5GHz radio and I am close to the router, I achieve 5G download speeds of over 600Mbps. When I’m further from the router (one floor down), the 5GHz signal isn’t sufficient — I have to use 2.4GHz. On this frequency, the download speed drops to about 1Mbps, and it doesn’t increase when I get closer to the router. Interestingly, at the same time the upload speed can reach, for example, 25Mbps — strange.

Sometimes, for the first minute or two after connecting to the WiFi router, the speed on 2.4GHz is higher — around 40Mbps, but after a short while it drops down to the already familiar 1Mbps.

I also checked that the problem isn’t strictly related to the 5G connection, because the same issue occurs when copying a file from a network share within the local network.

I’ve tried several solutions:

  • I created three different SSIDs – one with 2.4GHz only, one with 5GHz only, and one using both frequencies simultaneously, to confirm that the problem only occurs on 2.4GHz (on the combined SSID it happens when 2.4GHz is chosen automatically).
  • I changed the channel the 2.4GHz radio operates on - same problem. Generally there aren’t many WiFi networks in my area, so this shouldn’t be an issue.
  • I changed the transmit power settings and Country code – no effect.
  • I checked whether getting closer to the router helps – it doesn’t. I get a download speed measurement of 1Mbps even when the signal from the laptop shows -44dBm. The TX Rate and RX Rate shown on the router’s radio interface monitoring page aren’t reliable.
  • I can reproduce the problem on both the stable firmware and the latest firmware.
  • I was able to reproduce this problem on multiple devices

Is there anything else I can do to verify the router’s operation? Do you have any hints as to what might be causing this? Could the fault be on the router’s side?

Thank you in advance for any help!

2

Gonna try some more testing this weekend but if there is no solution I think I’ll decide to return the router while the free return is still available in the store. Slightly sad because I really wanted to support a European manufacturer and the product seems very promising.

3

I think I was able to pinpoint the issue and fix it.

While the problem seems intermittent and I am never 100% sure if it’s going to come back or not I was able to correlate it very strongly with bluetooth interference (since they share the 2.4GHz band).

  1. When a specific laptop had this issue I disabled its bluetooth adapter completely and I was able to see an improvement almost immediately.
  2. Re-enabling bluetooth sometimes causes the download speed to drop back down to 1Mbps but sometimes it can keep going with a very good speeds for an extended period of time.
  3. The problem could sometimes be fixed even by turning off a bluetooth mouse.

I was able to fix the problem by setting the 2.4GHz radio to use 20MHz frequency width instead of 40MHz. My previous router never caused this issue and I checked that it had an “auto” setting for the frequency width and no option to force 40MHz so I was not able to test the issue on it - that would be an interesting experiment.

For those interested in the details the problem was happening on devices with the following Wifi adapters with integrated bluetooth:

  • Intel Wi-Fi 6E AX211
  • Intel Dual Band Wireless-AC 8265
  • Intel Dual Band Wireless-AC 8260

Either way - fingers crossed that the problem won’t come back. I’ll need a few more days to make sure that the fix works reliably and it wasn’t not just a random occurence.

4

Hello @PGRoo,

Apologies for delayed response.

Could you kindly confirm whether the issue has been resolved, or if you still require any assistance?

Best regards,

5

Hi,

Yes, the issue has been resolved and I haven’t had this issue since.

Have a nice day!