Same problem as well, identical as described. Occurs on two separate systems, both with the AC7260.
One is a Sager NP9150, the other is an Asus UX301LA. Both running Windows 8.1.
After resume, the issue can be resolved by disabling and re-enabling the adapter.
The issue can be avoided by running an old driver version. 16.6.2.1 is the version I'm running.
I've been installing each new release of the 17 series to test in hopes of a fix but the same problem occurs every time.
This is 100% replicable.
Also, I am using WPA2-PSK, not TKIP. Issue occurs on both 5Ghz and 2.4Ghz bands. I am using the Netgear R7000 router, but router type doesn't seem to matter as the problem happens on resume regardless of my network environment and also occurs when I am traveling away from my home network.
As the flagship network adapter from an otherwise very good company, this should have been resolved by now.
I'd be happy to provide any more information to help troubleshoot and resolve.