Gigabyte z170mx-gaming 5 Alpine Ridge issue

[SmackAttack]

MODERATOR: please move to Hardware Support.

I've had a z170mx-gaming 5 (i7-6770k) machine for 5 years, currently running the latest Catalina with latest Opencore. I run an LG Ultrafine using an Alpine Ridge v2 card, but am needing to utilize the second thunderbolt 2 port on the AIC. BOTH ports work, but it seems, only one works at one time, swapping ports just moves one to the other.

I've combed through dozens of threads and haven't had any luck yet... all I'm trying to do is KEEP my LG ultra fine and add a BM Ultrastudio Monitor to the other port.

I'm NOT looking/needing any hotswap, just both ports working at the same time. I fear the Ultrafine is wiping out both, but am wondering if there's an SSDT I might need. The AIC is in slot-4.

Happy to provide further details, but for now, the only SSDTs I have are per the Dortianna guide, that being:
SSDT-EC-USBX-DESKTOP.aml
SSDT-PLUG-DRTNIA.aml
SSDT-UIAC-GAz170mx.aml

Thanks for any and all help with such an old, barely supported MB!

Best,
J

 

[SmackAttack]

I’ll add that the same behavior happens in Windows. Seems getting a second port working is a common issue with Alpine Ridge. I haven’t been able to update the TB firmware from 20 to 21 yet in Windows as the installer on Gigabyte’s page is down.