TV Shows library not working after restore from Time Machine backup

Hello and welcome to the Plex forums.

if this library is included on the dashboard, I simply get “There was an unexpected error loading the dashboard” when loading the dashboard

This would indicate there is a corrupted entry in your database. Please see our support article on a guide on how to fix the database. https://support.plex.tv/hc/en-us/articles/201100678-Repair-a-Corrupt-Database