I can't get 5.1 sound output

[Millmaxy]

Hi there,

New here. I have  an HDMI audio extractor for 5.1 surround connected to my display port (via an HDMI/DP adaptor). The only sound I can get to come out is stereo (L and R only). It has a light on it that's supposed to come on when it is receiving 5.1 signal. The light will not come on. It's not the device because this is the third one. I have configured the laptop output device to be 5.1 surround (side speaker version), It says "5.1" when I right click the sound icon. It says DTS and Dolby Digital are supported formats in "sounds" > "Playback" > "Properties".  I feel like the "Jack Information" shouldn't say just "L R" and needs to say all six channels; I have no idea why it doesn't or how to rectify that. Until just now I had been able to adjust the levels of all six channels (or see they were there) in the "levels" tab, but now it's just showing two channels. (Ran the configuration protocol again and now all six channels are back under the "levels" tab.) The speaker test within the configuration protocol has never produced sound from anything but the left and right front speakers; not even the sub. I have uninstalled and reinstalled drivers for everything I thought could be relevant. I have configured the device (or the DP rather) through the NVIDIA control panel. I had a Windows tech remote control my computer and check all the things I'd already tried and offer no new solutions (because I'd tried all the ones he can think of). I can find nothing that would make this impossible or imply that the way I have it set up shouldn't work. However in researching the issue it appears to be something Windows is actively not fixing because there are newer, better ways to encode sound for surround sound. (WHO THE HELL ASKED FOR BETTER AND NEW?! CHILL OUT WITH ALL THE **bleep** TECHNOLOGY FOR A SECOND!!!) Please send help. I don't want to get a new computer and have this happen again for no apparent reason. I have TWO sets of 5.1 speakers that I can't fully use until I figure this out. Thank you.