[UE5] Crash while rendering Movie Render Graph

I’ve recently started using Movie Render Graph and I’m getting a crash during the render warm-up phase on a post process material:

Fatal error: [File:W:\UEBuilds\mue560.src\Engine\Source\Runtime\RenderCore\Private\RenderingThread.cpp] [Line: 881]
Rendering thread exception:
Fatal error: [File:W:\UEBuilds\mue560.src\Engine\Source\Runtime\Engine\Private\Materials\MaterialRenderProxy.cpp] [Line: 520]
Cannot queue the Expression Cache for Material MID_pp_outlines_168 when it is about to be deleted

0x00007ff642a1c677 modus-Win64-Shipping.exe!UnknownFunction
0x00007ff641b5e0d1 modus-Win64-Shipping.exe!UnknownFunction
0x00007ff63fc314bb modus-Win64-Shipping.exe!UnknownFunction
0x00007ff63fc45d61 modus-Win64-Shipping.exe!UnknownFunction
0x00007ff63fc402b1 modus-Win64-Shipping.exe!UnknownFunction
0x00007ff641b75df7 modus-Win64-Shipping.exe!UnknownFunction
0x00007ff641b75f07 modus-Win64-Shipping.exe!UnknownFunction
0x00007ff63fe26c8a modus-Win64-Shipping.exe!UnknownFunction
0x00007ff63fe26b69 modus-Win64-Shipping.exe!UnknownFunction
0x00007ffbe223e8d7 KERNEL32.DLL!UnknownFunction

It seems to only happen when the Preview Widget is up. Does anyone have any ideas why this might happen?