After 2 trouble tickets and multiple phone calls, I have gotten no where. Support keeps telling me that the problem is with the TV network. I have pleaded with support to have FIOS techicians call the Golf Channel technicians to get this fixed but they apparently do not want to be bothered.
This bug appears to be a regional issue because I talked to FIOS support in Syracuse NY, and they do not see the problem. I sent an email to The Golf Channel but they have not responded. Today I sent an email to NBC Sports and got an automated reply. They must have a trouble ticket system. This looks promising but I will just need to wait.
For the record, the problem happened in the middle of a program last night. I was watching the Indycar race on NBCSN and it flipped from full screen HD to letterboxed.
See the video here: https://drive.google.com/file/d/1Yege9CG1QrUtoBLRche_S-n9P1CxVXyF/view
To anyone who reads this post, I ask that you periodically check 590 and 593. If you see an HD program that is letterboxed, please call FIOS support and request that it be fixed. If enough people complain, then maybe we can get some action from Verizon.
Thanks.