I think the problem is that even though you have linked it to a TV series, you don't yet have it linked to episode data. Until episode data is linked, it doesn't reveal the TV series underneath.
Two ways to link it to episode data:
A) [Recommended] Use the Discs(s) button to link it to the source DVD/Blu-Ray, and then map the episodes.
B) [Alternative] Click the new "Edit Episodes" button that showed up next to the TV Series button you clicked before, and then Add episodes manually.
As soon as you do either A or B, even if just for a single episode, you can click save and the TV Series, Season, and Episode data will appear in the tree beneath the disc.
If you're curious why A is recommended, it's for those of us that play episodes from disc or ISO or folder rip, by having it mapped then we can directly play the episode without having to use the disc's menu, which can be klunky. My software, CMC, uses the My Movies disc episode mappings to permit direct play of episodes, it's pretty awesome.
The B option exists so that if you don't have the discs to map episodes, and no one else has already done it for you, but still want to access the episode data, you can.
Hope that helps.
Paul
Chameleon MediaCenter (CMC) v5.0 - A FREE WMC replacement GUI for My Movies Collection Management on Win7/8.1/10/11, plus a Music Library and App Launcher!