Many years ago I had a similar experience with my xonar d2x soundcard when my optical port died. I sent it in for repair and while they replaced the port they returned it to me in a nonfunctioning state. My subsequent rma's have all turned out better with great service.
Asus ROG Crosshair VIII Hero Wi-Fi Gigabyte X570 Aorus Master, AMD 3900X, EVGA 360 aio, 32gb G.Skill Trident Z Neo, Samsung 970 Pro NVME 512gb, WD Black NVME 1 TB, Crucial MX500 2tb, Zotac GTX 1080 AMP!, EVGA Nu Audio, CM HAF 932