Hi there, same problem here like the thread-creator...
I check all cables
update all divers (wigig-card and graphic-card)
I try the PCIe WiGig card in two card-slots (with new driver un- and reinstall)
and I tried removing SteamVR/Vive USB drivers (https://support.steampowered.com/kb_article.php?s=6643267c2b51f08c93e8fc35bf35aa48&ref=2748-WEIK-9562)