First of all my modem is v1.2, just couldn't select it above. Using latest firmware, of course.

I love this modem's performance overall, Wi-fi signal is good around the house, cabled connection on my PC has no problems. However, wi-fi has one big problem. My internet connection stays stable but all other devices connected to my modem in the house disconnects from internet. Notebook, 3 smartphones- poof, connection gone for no reason. They can't be connected to the internet without restarting my modem, even i have no problem on my desktop PC, I have to resart my modem to let my family connect to internet with their devices, which is frustrating. They can see wi-fi network, just can't connect to internet. Not using any wireless extenders etc.

I tried doing things like;

Toggle 5GHz wireless off/on (normally they are,2.4-5GHz, both ON)
Changing lease duration to 2880 
Changing wireless channel to 11
Changing wireless to Auto/20/40MHz
 

None of these worked. Wireless devices still disconnect randomly. I don't know what should/can i do.

Wi-fi is working on b/g/n btw.