Network / Sharing :: Can't Access Certain Sites Until Reboot - TCP / IP

So yesterday I upgraded from a slow, ancient T1 to Verizon's "Home Fusion" 4G LTE broadband. It's amazing how fast it is, but I seem to have a problem where occasionally I can't connect to certain sites.

For example, I'll be surfing Facebook and all of a sudden it'll just stop connecting and I can't do anything. BUT if I jump over to my laptop (running Windows 7) or my iPad, both of which are on the same network, it works fine.

If I then reboot the Windows 8.1 PC, all of a sudden I can access Facebook again, for awhile, until it craps out again at some point and I need to reboot again. It's not just FB either. This happens with a handful of other random sites as well, but when it does I can still access 99.9% of other sites just fine.

One thing I've noticed is that whenever I can't load a site, it seems like it's almost always waiting for some type of CDN-based content to load. Often if I hit the stop button in the browser the page then shows up immediately.

Like when I first tried loading this site, it just sat there forever and in the lower left corner of the browser it said "Waiting for yui.yahooapis.com" then after awhile I just hit X and then eightforums displayed just fine...

Browser doesn't matter. I've tried them all. I've tried flushing DNS, resetting winsock, etc. and nothing works except rebooting. Another odd thing I noticed while messing around is that I don't seem to have a HOSTS file in the normal location. I can't find it anywhere??

At first I thought this new verizon router just has flaky wifi so I switched to a direct connect via ethernet hoping that would solve the problem, but nope. It's definitely not that because like I said when it happens I can jump on my laptop connected to the same network via wifi and I can connect to FB just fine on that machine.

Both machines are running the same firewall/antivirus setup, and this Windows 8.1 machine is free from all malware, rootkits, etc.

Yesterday I tried testing different DNS servers (Google, OpenDNS etc) but that didn't work. But it did lead to something else weird - today if I try to do the same by opening up the TCP/IPv4 properties for my ethernet adaptor I get the following error message:

"In order to configure TCP/IP, you must install and enable a network adaptor card."

I just tried re-installing the latest drivers for the ethernet adaptor but that made no difference (it's an onboard Intel I217-LM). I've also tried different/new ethernet cables just for kicks.

I'm starting to wonder if the fact that my connections look like a mobile phone while my browser headers/useragent etc. identifies them as coming from a desktop machine is confusing some sites/CDNs, etc.?? Although that means all users of Verizon's Home Fusion service would have this problem and that doesn't seem to be the case.

I guess the weirdest thing of all is that if I can't connect to a site like say FB, if I just reboot then I can connect to FB again for awhile, until it decides to crap out again.