Can someone let me know what I'm doing wrong?
You're not providing guide data to Channels DVR for your sources.
Double check your source settings and check the DVR log for errors.
Are there instructions for providing guide data to Channels DVR? I have searched the groups but may not be using the correct key words? I appreciate your help.
I inserted the URL for an EPG in my Custom Channels page but am still not getting anything in the Guide except the channel name. Can someone help point me to what I am doing wrong?
I suspect the tvg-id in your M3U doesn’t match the tvg-id in the XML. Think of that field as the “master name” that links them both together. So basically channels doesn’t know what program matches what channel.
I also wonder if it doesn't like your .xml.gz compression???
Maybe someone would comment on if they have used that before...
Or you may what to just expand it locally and point to that and see what happens. 
Most likely the M3U tvg-id doesn't match up with xmltv epg <channel id> and <programme channel>
Channels DVR does support gzip compression for xmltv guide data