Around a week ago, my ROG Delta S stopped working. Ever since I bought my ROG Delta S a year and a half ago, it has had a lot of issues. For example, it's wire kept breaking or audio had issues (Solution: Made custom wire for headset that I still use). Now, whenever I try to connect my ROG Delta S to any port on my computer, it always says 'USB device not recognized'. I also use the original adapter for USB A. My headset is still not working.
If your ROG Delta S headset isn't being recognized using the original usb-c to usb-a adapter cable, then I suspect something with your custom made usb-c cable.
I understand that the wire may be part of the problem. However, when I do connect my ROG Delta S headset to the USB port, the lighting automatically starts breathing red color (except if lighting is turned off). This happens on both Soundwave and Custom RGB effect lighting.
Some usb-c cables are for charging only, some usb-c cables can transfer data which is what you need.
I'm leaning towards your custom usb-c cable is only a charging cable.