Oh, you didn’t say Mac....😥
Yes, it does make a difference, quite a large one.
If you have Parallels, and a WinOS under it, you could run that up and try in Windows, but you probably haven’t?
I’ll run up my Mac tomorrow, and see what I can see, but my only observation about the Mac app so far is that it was dreadfully fuzzy for me.
What Mac, and what MacOS, are we talking about here?
Hopefully, yours is not too dissimilar to mine.
I can’t reproduce your issue... here I am with NowTV up in the Safari browser, Tin Star added to, and chosen from, my Watchlist. And I’ve just scrolled up about 5 presses on the keyboard Down Arrow (though I could equally well have used the mouse), and you can see the selection buttons for Seasons 1 and 2, and you can see that further downward key-clicking or mouse-scrolling reveals the individual episodes that I can click on directly to play the one I want.
macOS Mojave 10.14.6 on my iMac Retina 4K, 21.5-inch, Late 2015
Can you post a picture of what you get?