Z790-E Line-In audio low and spikes at high volumes

[Exubun]

This video shows the issue. https://streamable.com/7h6sxc

I've spent all day isolating this issue of my audio spiking from my Line Out cable into my Line In on the motherboard.

I've installed the lastest Bios, Drivers, replacing cables, and the whole 9-yards of uninstalling and windows troubleshooting.

I believe it might either be a defect or driver issue with my board. I would like to ask anyone else with a Z790 board to try plugging in an audio input device into the light blue port (Line In) and see if this issue also occurs for you.

I found a workaround at the moment plugging my Line Out cable into the Mic In port to play audio to my speakers.

[DeusNoctem]

I feel the pain. Any updates/fixes found?

I recently built a new PC with an ASUS Z790-E and connected all my previous audio peripherals and cables. I found that there is an audio dip/spike using the Line In (listening to my GoXLR - System Sound). 

Same setup as far as peripherals and cabling, only difference is the MB Line In and it’s audio output dips/spikes. Which is highly annoying. 
I have tried various fixes for the ALC4080 found in some searches, but nothing lasting. Every now and again when you reinstall the driver it works until a reboot/shutdown of the PC. Then the audio continues with the normal dip/spike.