Compatibility issues with Samsung LCDmodelun55B8000 XFXZA

I have a Samsung Lcd/Led tv model UN55b8000XFXZA. The last year it has been hooked up to Comcast with no issues. Recently I changed service to Verizon/fios which provided a Cisco box. Now the tv when in the high deaf 1080 option cuts off the left and top of the screen because it is magnified. I have checked the settings both in the verizon box and the Samsung tv and they are both set to the appropriate settings. Has anyone else had similar issues and if so can you advise if there is a fix for the problem. The only solution I have found is watching tv in a lower resolution which defeats the purpose of fios. Verizon claims it is a samsung issue, samsung points fingers at verizon. Thanks for your help hope to here from someone with a solution.