Display not refreshing properly on 6.12

Brief summary of the problem:

On Linux 6.12 (bisected down to commit bd8a9576617439bdc907c9ce0875909aea4221cb), my display doesn't refresh often. In particular, it seems like it (semi-consistently) only refreshes once every couple seconds unless there is mouse movement. The issue is also present in newer versions of 6.11.x.

Hardware description:

• CPU: AMD Ryzen 7 7840HS
• GPU: AMD Radeon RX 7700S (discrete) and AMD Radeon 780M (integrated, in use)
• System Memory: 30.66 GiB
• Display(s): 2560×1600 @ 165 Hz with VRR (Framework 16, "BOE 0x0BC9 Unknown")
• Type of Display Connection: eDP

System information:

• Distro name and Version: NixOS (unstable)
• Kernel version: 6.12.0
• Custom kernel: Taken directly from Linus's tree on GitHub
• AMD official driver version: N/A (whatever NixOS does)
• Compositor: Sway 1.10

How to reproduce the issue:

Not sure how reproducible this is since I only have one system to test it on (Framework 16 w/ dGPU), but it happens consistently for me.

1. Use a kernel with the changes from bd8a9576617439bdc907c9ce0875909aea4221cb;
2. Boot system and launch Sway 1.10 (haven't tested other versions) with adaptive_sync enabled, or gamescope with --adaptive-sync;
3. Try interacting with the system without touching the mouse;
4. Effects are quite obvious trying to type in a terminal, and feel like input lag.