ACES render colours randomly go muted - help!

I've got a composition built up of some light passes from Maya & V-Ray 7. Rendered with ACES 1.2 Config.

These are added on top of each other to match a result that I get in Photoshop for a product render.

On top of these are some adjustment layers with various exposure/hue sat/curves etc.

When I RAM Preview the animation without the adjustment layers it looks fine, then with the adjustment layers it'll be fine up to a point then the colours will go all muted. The individual light comps and beauty pass look fine on their own... No flickering or muted colours.

I've tried this setup via the new OCIO Color Managed set up in After Effects, and via my old method that was to use an OpenColorIO ACEScg > sRGB adjustment layer with a Color Profile Convertor layer on top to correct the gamma.

Both of these methods have very much random issues with the frames going muted on random frames. If I turn any adjustment layer off the muted look disappears. I've tried to reset AE preferences, have updated to the latest version, and flushed the cache but this doesn't fix the issue.

Might anybody know how to fix this? I need to get an animation rendered really urgently.

Using Windows 11 and AE 25.5 Build 4, with ACES 1.2 Config.