The Cloth simulation time step smoothing is interfering with the substepping fix for multi Temporal Samples by changing the very variable DeltaTime and causing some large errors in the cloth simulation due to increasing/decreasing convergence.
Simulating with p.ChaosCloth.UseTimeStepSmoothing 0 fixes the issue.
This Cvar needs to be added to the MovieRenderPipeline startup sequence to solve this issue for everyone.
Cloth or hair , it is the same Chaos Physics , Should be fixed in UE5.2 😁