That pass through might be restriicted, blocked or degraded through the HDTV. Bluetooth is usually stereo (99.99% of the time) so if you are trying to pass 5.1 sound it might go silent.
This area is well worn but I understand folk are going to bump into this over and over.
Also, an input has no sound output. I'm sure you meant something else but wanted to be painful crystal clear because I did encounter too many setups where they connected the TV's input jacks to their receiver's input jacks and wondered why nothing happened.
We are not getting sound out of a Denon AVR 1312 receiver. We have DirectTV connected to the Denon via an HDMI cable. Using the HDMI out the Denon is connected to a Sharp TV. We then connected a Vizio 5.1 channel sounbar system to the Denon using an optical cable. We are getting no sound from the TV input. We were able to get sound from the speaker system using the iphone and bluetooth, thus the speakers appear to be working. Looking for help on what the problem might be. Thanks