Are you running Windows BOOTCAMP or using Apple OS on your laptop?
I would first find out if there are drivers for the AMD Card you want to install from APPLE on your Apple laptop using Apple OS or Windows BOOTCAMP
Found this review about the Razer Core X: Razer Core X Review & Rating | PCMag.com
Copied from above Review:
Successfully powers non-Razer laptops with Thunderbolt 3, including select MacBooks. Accepts three-slot-wide video cards. Higher-wattage power supply.
Bulky. Not quite plug-and-play for non-Razer laptops. Mac compatibility has limitations. Some performance loss compared with desktop-PC installation.
The Razer Core X drops some of the high-end features of its Core V2 sibling, but keeps most of its external GPU functionality for $200 less. Setup can be a challenge, but it works with a range of laptops, including some MacBooks.
Also another review: Razer Core X - Full Review and Benchmarks
Similar to the Core V2, the Core X supports a multitude of GPUs, including workstation-grade cards like those in Nvidia's Quadro line and AMD's Radeon Pro series of cards. And thanks to the Core X's bigger dimensions, it can also house ridiculously powerful graphics cards like the GeForce Titan V or the AMD Radeon RX Vega 64.
Similar to the Core V2, the Core X doesn't discriminate between laptops with dual or four-lane Thunderbolt 3 ports, which means that as long as your notebook has the right port and software, you're good to go. For the software, PC users need to have at least Windows 10 64-bit, while Mac users require at minimum High Sierra 10.13.4.