BTW, the same issue with no internet (AC3100 in my case). Unfortunately, I have to revert back right now, so here is all information that I can provide atm:
- internet connection through PPPoE
- internet connection is available immediately after router reboot. but drops after some time (and there was no internet on the first boot just after firmware update). when issue occurs - internet is available from router itself, but not for clients (tested both from wired machine and wifi) - so looks like routing/firewall issue
- I have Skynet installed - who knows, maybe it's related...