N64 RGB Mod: Sync Issues with EverDrive 64?

Hello everyone,
ragdoll hit
I'm hoping someone here might have run into this specific issue. I've got a stock N64 (NUS-CPU-04) that I've recently modded with a Tim Worthington RGB board. It looks incredible on my monitor with original game cartridges, and the picture is perfectly stable.

However, when I use my EverDrive 64 (v2.5) to play games, the picture gets really unstable. It'll get a little wobbly, and sometimes the whole screen will lose sync for a second, especially during fast-paced scenes or scene changes.

I've already re-flowed the solder joints on the Tim Worthington board just to be sure, and I've tried a different power supply, but the problem only happens with the EverDrive. Original carts work flawlessly. This leads me to believe it's some kind of sync-on-luma signal issue specific to how the EverDrive outputs its video signal.

Has anyone else experienced this specific sync instability with a Tim Worthington mod and an EverDrive? Is there a known fix or a setting I need to adjust on the EverDrive itself that I'm missing? Any advice or guidance would be a huge help. Thanks in advance!