After waking up my laptop (Acer E571G, Windows 10, Qualcomm Atheros wifi module) from sleep it sometimes says no Internet. Wifi seems to be connected, correct IP address is received from DHCP but cannot ping anything neither on LAN nor WAN. It's as if the router stopped routing. My 802.11n Android phone also stops connecting when this happens. 802.11g devices still connect fine, and I can also reconnect my laptop if I force the wifi module to 802.11g mode in Device Manager.
The only thing that fixes this is rebooting the router. I tried a lot of various configurations and three different firmware versions, nothing helped.
Any tips are appreciated.