Adaptive-Sync not working with HDMI 1.4

Monitor is the Asus VA24EHF, which is Adaptive-Sync compatable.
GPU is the AMD RX580.
Asus website says the HDMI cable is 1.4.
However, there is no free-sync option in the display settings of either the Wayland or X11 session. I’m using Arch Linux installed via Arch Install the latest version of KDE Plasma installed.

Some things I have tried to no avail:

Using the base Linux kernel instead of tkg
X11 session

I’m more than willing to provide more information to help troubleshoot this issue if you want.