Steps to reproduce:
Start Emby Theater Click on Live TV Click on...
Program under "Now Playing" and it works fine.
Guide -> the title of the program that is on now -> Play and it shows loading animation but doesn't playback the program.
Server log attached. I tried the latter at about 3:37 and 3:40, maybe 3:42 too. Then I tried the Former two times after that. Every subsequent test was the latter.
server-63615369600.txt