I have a HDHomerun and 2 streaming sources, resulting in several duplicate versions of the same channels. I thought they were supposed to combine into one entry for the guide, but I am not seeing this happen.
All of my locals are duplicated and show as channel 2 for the streaming source and 2.1 for the HDHomerun source. Guide data is identical and the mapping shows them both pointed to the same station (i.e. 2 and 2.1 both show mapped to WESHDT (NBC).
Is there something I'm missing somewhere?
in the server gui - Advanced / Expermental / De-duplicate HDHomeRun Channels
client settings - Manage sources / stack duplicates / by guide data
having said that, I have noticed duplicates in the guide recently (past few days, or maybe weeks not sure since most of my duplicates are tve and way at the bottom) (also have made lots of changes to my custom sources lately, so been assuming I messed up somewhere.)
I"m using latest beta server, gtv client, and experimental guide view
Thank you - I was missing the client side setting
glad it was easy! 
my issue was caused by some extra custom channels i set up.
apparently it will only de-dup between different sources, if you have duplicates in a single m3u it will always show the dup in the guide.