well sometimes plex gets jacked up when removing and/or re-adding a tuner.
You might have to restart the server and give it some time to process before making any dvr tuner additions/removals.
In any case, to get to the premium tv guide (from what I remember) after plex scans for the channels and attempts to match up a guide, there is an option to manually choose a guide for either OTA or CABLE.
in the drop down should be listed all of the guide/cable providers, which should include the hdhr premium guides.
I posted a detailed walk through on some other thread awhile back, I’ll see if I can find it and link it here.
edit
@michigas see @ HD Home Run and Preium TV guide
