On the web app, Fix Match is missing specifically in a few locations in the TV Shows library’s Recommended section:
-On Deck
-Recently Released
-Recently Added
-Continue
-Recently Watched
Fix Match is available in all other locations of Recommended and doesn’t not appear as an issue under Movies and Music libraries.
Work around: go to TV Shows > Library and Fix Match from there.
I don’t use the ‘On Deck’ or ‘Recently…’ hubs, but I’m pretty sure they only list episodes. But Fix Match can only be done for the entire show, not individual episodes or seasons. That’s why Fix Match doesn’t appear in the On Deck and other hubs.