I don't have any info on what OOMA devices might do to impact the networking experience. There shouldn't be ANY impact, but a quick test would be to disconnect the OOMA device from your network and reboot the cable modem and see if anything changes.
Assuming no changes:
First, make sure you are have all Windows Updates installed, including the big OS November update to TH2 1511, build 10586. Check device manager and confirm that the Marvell driver version ends in .47. If you aren't on 10586 with this driver, check Windows
Update and install whatever is offered.
There have been quite a few similar reports from folks running a few ASUS routers. There's some compatibility issue here, and it is up to Microsoft to diagnose and get new drivers to fix this.
I don't know how long it will take Microsoft to provide a fixed driver (they have not commented on any of the posts where the ASUS routers are mentioned and the regedit does not work). If you don't want to wait for a fix, you can throw money at the problem
and buy a different router. If you decide to replace the router, the community can make recommendations on which ones work.