(GNOME) After kernel upgrade VRR is broken on main monitor

[JohnTheCoolingFan]

I am using distribution kernel (sys-kernel/gentoo-kernel) and just upgraded to 6.18. Currently I have 6.12.68-gentoo-dist and 6.18.8-gentoo-dist installed. Booting into 6.18, I've discovered that I no longer have an option to use Variable Refresh Rate on my main monitor, but it is still available on my secondary monitor. I've enabled the experimental feature in GNOME to even be able to use vrr at all, and it has been working fine on 6.12. I've checked the edid, and it's identical between boots, and has variable refresh rate capability:

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  Vendor-Specific Data Block (AMD), OUI 00-00-1A:
    Version: 2
    Feature Caps: 0x01
    Minimum Refresh Rate: 48 Hz
    Maximum Refresh Rate: 75 Hz
    Flags 1.x: 0x00
    Flags 2.x: 0x00
    Maximum luminance: 0 (50.000 cd/m^2)
    Minimum luminance: 0 (0.000 cd/m^2)
    Unknown: 0x00 0x00

gdctl -v reports no vrr on the main monitor on 6.18, but does have the variable refresh rate property on 6.12:

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Monitors:
├──Monitor DP-1 (Shenzhen KTC Technology Group 27")
│  ├──Vendor: SKG
│  ├──Product: DEXP DQ27N2
│  ├──Serial: 000000000000
│  ├──Modes (55)
│  │   ├──2560x1440@75.123
│  │   │   ├──Dimension: 2560x1440
│  │   │   ├──Refresh rate: 75.123
│  │   │   ├──Preferred scale: 1.0
│  │   │   ├──Supported scales: [1.0, 2.0, 3.0]
│  │   │   └──Properties: (0)

GNOME version 48.5, wayland session. The GPU is AMD Radeon RX 6700XT (so the driver is amdgpu), the main display is 2160x1440 75Hz, connected via DisplayPort, the secondary display is 1920x1080 75Hz connected via HDMI. There is a third display, connected via displayport and a DP-to-VGA converter/adapter, it doesn't have any VRR capabilities and shouldn't be relevant.

I recall having this issue with some version between 6.12 and 6.18 that I tried because of ntsync, but can't recall which version it was.

I have been trying to figure out the cause or at least the place where the break happens, but to no avail. Has anyone also experienced this, or have ideas as to what might be the cause?