For a few months now, I have had no sound come from my built-in monitor speakers. I just now switched out the monitor cables and found the issue, but I am not sure how to fix it. The sound from the monitor works when I plug my graphics card into the HDMI port of my monitor. However, upon switching to a DisplayPort cable, there is no sound from the monitor. I have tried fiddling with AlsaMixer, and when I select the AMD GPU as the sound device, every parameter is set to zero and I cannot change it. My GPU is an AMD FirePro S10000 and I am using the default AMDGPU drivers. I am not sure if the DisplayPort cable itself is the issue, because the HDMI cable was very cheap, but the DisplayPort cable is made by Club 3D and is VESA-certified. Please let me know how I should go about trying to fix this issue, as I am running out of ideas on what to do. I cannot use HDMI since I have a 4K monitor, and only on DisplayPort can I run it at 60Hz; HDMI maxes out at 4K 30Hz.
I also tried turning off DisplayPort 1.2 capability in my monitor, but that did not do anything.