Hi,
I am a Microsoft Certified Professional who can help you with this issue as i have seen many scenarios like this with many Windows OS starting from Windows 2000 to the latest and greatest Windows 10.1 OS.
I also worked with many Internet Service Providers with various modem/router configurations such as MAC Address cloning, Bridged,Unbridged hand-on experience both with wired/wireless network configuration and troubleshooting.
If the proposal presented is satisfactory and believe that i would be able to help you fix this issue.
Give me a opportunity to work with you to display my skillset.
Thanks,
Vignesh S.