Hi jodiuh, welcome to ROG Forum.
I do not like or use W8/W8.1, so my suggestions are based on W7, but i think they are also applicable to 8/8.1.
First of all, i think the issue could be with the router / modem connected to the motherboard, so, if you have another one, you could try it and see the results.
By the way, i’m also on a M6H and it is connected to a Cisco firewall ISA 570 and each time the mobo resumes from sleep, the Internet connection is always immediately on, a sign that NIC, IP addresses, etc, is all ok.
To leave out any doubt, i suggest you go to Task Manager > Sevices Tab > Services...> DHCP Client > right click Proprieties > check if the service is config. as “Automatic” and it is running.
2. A workaround to this issue could be to assign an IP address to the NIC, and as in my case the firewall/router almost always automatically assigns the IP address 192.168.75.100, if i had this issue, the config would be:
As you can see i’m not using TCP/IPv6, and if you use it, maybe you have also to config it.
Sorry if you already have tried this, hope this could help.