Cable Matters USB-C to HDMI 2.1 Adapter (201388)

Name: Cable Matters USB-C to HDMI 2.1 Adapter (201388)
Brand: Cable Matters

Here is a closer look at Cable Matters USB-C to HDMI 2.1 Adapter (201388).

About

A Synaptics VMM7100-based active adapter rated for 8K@60Hz, 4K@240/120Hz with HDR. Its firmware has repeatedly disabled VRR to fix black-screen instability translating FreeSync/VRR frames into HDMI Forum VRR on AMD/Linux hosts — a known limitation of PCON adapters on non-Windows systems.

HDMI version: 2.1
DP Alt Mode: Yes
Max resolution: 7680x4320@60Hz
Requires DisplayLink driver: No

Ports: 1× HDMI

Confirmed with

Notebook (generic)
Community troubleshooting found this adapter needed a firmware update from v6.03 to v6.05 to resolve display incompatibility — confirmed working on an ASUS ROG X13 (GV301QE) after the update, while an older Alienware R8 desktop still failed.