Note: This isn’t necessarily related to your issue, but you might consider changing the repository for your jail off the default quarterly setting. 1.19.4 is not the latest version available on pkg. Latest for stable is 1.19.5.3112 and plexpass is at 1.20.0.3133.
Regarding you issue, Plex does not support .nfo files.
If you manually match a title sometimes I find I have to run a manual refresh on the metadata for the series to get it to kick over and actually pull in info for all the existing episodes on disk. After that you should get info for newly-added episodes, but that also depends on what’s at TVDB. I’ve noticed lately many just-aired episodes don’t have their titles when I sit down to watch them (let alone synopsis), and they only gain them a few days later. I’m not sure if this is a caching problem or the info simply has not been added to the TVDB yet by anyone. I haven’t looked to closely into it.
