Dear Readers,I've a strange issue that I've been struggling for a week. I bought an LG43UJ634V UHD TV and an LG LHB645N Home Theater in a Box system.I use HDMI ARC to connect the audio from the TV to receiver. LG has an option to chose between PCM or Auto at the Digital output settings.If I use the PCM option everything sounds great, but I don't have 5.1, only 2.1.And here comes the problem. When I choose Auto, 5.1 is on, sounds great but I have occasional popping noise (like when play something on an old LP player) it happens random, but for example during a film, it is very annoying. It happens with YouTube, Netflix, DLNA streaming, external devices, so the content doesn't matter. I think I've tried everything. I tested it with different HDMI cables, optical cable, but still have the problem. I tested it with a sound bar as well, the problem is the same.When I play content from the receiver, there is no problem, the sound is wonderful, no popping. Also, the TVs speakers are okay.I don't think it is a hardware issue, because the TV's sound is OK, the home theater's sound is OK, the problem only happens when I want to use the digital output of the TV (either HDMI ARC or Optical) with auto setting.I called LG as well, the rep. said the she will pass this info to the technical team.Do you have any idea, that it can be solved, or I need to wait for a software update?