JDS tends to be overly concise, since most of the details are spelled out in the postings that he links to.
Cable boxes tend not to interact well with the HDMI repeaters used in receivers. When they have problems, the best workaround is to connect to the TV using HDMI (if the TV supports it) and to the receiver using S/PDIF digital audio (either optical or digital). No audio capability is lost because it isn't there to begin with. TV and cable channels use either stereo PCM or lossy Dolby Digital audio. They do not use DTS or the lossless Dolby encodings.
The major problem might be lip-sync of the audio. You might have to make adjustments in the TV or the receiver to match the audio or video delays.
Marantz SR7009 avr + MM9000 amp --> Atmos 7.1.4
Fronts=NHT 2.9+AC2, FH+TM=DefTech PM1000, LCR+TM amped