PROBLEM SOLVED!!
I have been using the Fios app for years on both an android phone and an iPad. Yesterday, both devices suddenly started telling me that I couldn't access certain channels because I wasn't on my home wifi, even though I most certainly was. I spent hours deleting and reinstalling apps (both the old FIOS Mobile app as well as the new FIOS TV app), logging out and logging in, and resetting my router.
Finally, I decided to turn to my set-top box. From the STB, you can run an auto-correct process to self-diagnose and clear problems with the STB. Well, it must have found something to fix because once the STB was reset and restarted, both apps can now see I'm at home and all is good. I don't know if the problem was only the STB or a combination of all of the other things that I did as well.
Here is the procedure to run the auto-correct process through the STB:
From the Main Menu
--> Customer Support
----> Top Support Tools
------> Fix FIOS TV Issues
This will bring you to an screen that says "Auto Correct My STB/DVR". Select your main STB from the list and follow the prompts to run the diagnostic and reset procedure. It will take several minutes until the box is up and running again.
I want to make sure that I posted my solution after finding on these forums that nobody else was able to clear this problem.