I have a peculiar setup, with a pc and Fire TV as inputs and a 4k Eizo monitor as output, connected with display port and HDMI. Sonos system as audio. (arc/era 300/sub and now Arc Ultra)
In Windows 11, the two monitor connections are seen as two different monitors, so I mirrored them in display options.
I use the two connections because my monitor is 4.4.4 10-bit through the display port and 4.2.2 10bit through HDMI. For photo retouching like I do, chroma subsampling is not good. But I need HDMI for PC audio.
The VAX04101 worked straight out of the box even with a not perfect HDMI cable to the monitor (as I discovered later) but I had to use 5.1 EDID, that granted me Atmos on Fire TV and PCM multichannel 5.1 on PC. It was fine I thought I did not need Atmos on Pc.
At some point in time, I contacted customer support and explained my situation, and even after all their suggestions, I was stuck where I was before. Then, they sent me a firmware upgrade. Before updating, I tried a different full HD monitor, and then I could hear sound from the PC with EDID 7.1, but still no Dolby atmos. The Dolby access app setup wouldn't work. I tried to change the HDMI monitor cable, nothing new on the audio side, but I had 4k video on my primary monitor with EDID 7.1 on the Vax. (before, it worked only on 5.1). Ultimately, I did the firmware upgrade, and everything worked out well. I have Dolby atmos on both PC and Fire TV.
As you can see, my setup is very complex to troubleshoot, including the exotic monitor, PC, and all its software. But Henrik from support helped me in every step with patience, kindness and fast response.
I couldn't be happier with the product and the experience with Feintech. This VAX04101 is a lot cheaper than the only worthy alternative, Fury Arcana and a switch, which will cost double the price.
The people at Feintech are great, and there is nothing more to add.