NBG-460N drops Internet for everyone when new device connects

Ig0r

I've noticed a problem with my Zyxel NBG-460N EE:

I have several devices (laptops, TVs, smartphones) connected to wifi, and everything is working great. Until I connect another device to my wifi network. Sometimes it's my iPhone 6S. I enable wifi on iPhone, and as soon as I get a connection - all laptops go offline.
Sometimes it's my second laptop - if I turn the wifi ON on it - only that laptop gets an Internet connection, leaving all previously connected devices without the Internet. They show that they are connected to wifi, but no Internet.

The only way to get Internet back is to turn off and on wifi on every disconnected device.

At first, I thought it might be a problem with different wifi standards? Maybe Zyxel is trying to alternate between b/g/n all the time? But all my devices support wifi N-standard and have it enabled!

- I don't want to downgrade my network to G-standard.
- I do have the latest firmware version (V3.60(BFL.1) | 07/06/2010).
- I've tried resetting Zyxel, it didn't help.
- I've tried to change wifi channels twice, it didn't help.

Mybe someone experienced something similar and can help me? Thank you!

#Router_December