All my family calls on me when they need TiVo help, imagine my surprise when a family member called to ask about Netflix not being on their now playing list or in the Find TV, movies, and video list then when I pulled up my TiVo to walk them through trouble shooting, mine was gone too.
Interestingly when I went to Find -> browse->available from, Netflix was there. But choosing Netflix did nothing or popped back into main menu.
We both had the same issue/resolution, so here it is in case it helps you.
We went to Settings and Messages ->Settings->channels-> video provider list
but the list was empty!
We exited the menu and came back several times and it finally showed our our selection. Just in case it helped we unselected Netflix and selected it back, but that may have not been necessary. When we returned to Now Playing and search Netflix, was back and the available from icon worked.