This is a regression
Tested in:
//UE4/Release-4.27 CL18319896 Binary
//UE5/Release-5.0-EarlyAccess CL16682836 Binary

Under the same conditions in UE4 the On Hit events fire accurately and as expected. In UE5 the On Hit evets are sporadic and inaccurate. Observing the ball closer some times it doesn't connect with anything and starts bouncing up.

Steps to Reproduce
  1. In Project settings enable Substepping, enable Use Fixed Frame Rate, and set Fixed Frame Rate to 15.0
  2. Create a New Level using the Default Level Template(so we have a floor)
  3. Create a Bouncy Ball actor:
    1. Create a New Blueprint Actor named Bouncy Ball
    2. Assign a Static Mesh Sphere as its root
    3. Enable Simulate Physics
    4. Enable Mass (kg) then set it to 1.0
    5. Enable Simulation Generates Hit Events
    6. Collision Presets should be set to PhysicsActor
  4. In the Event Graph create an On Component Hit(StaticMesh) event
  5. Drag off the execution pin then create a Print String node
  6. Create then assign a Physical Material for the Bouncy Ball actor:
    1. Create a new Physical Material
    2. Set Restitution to 0.9
    3. Enable Override Restitution Combine Mode
    4. Set Restitution Combine Mode to Max
    5. Assign the Physical Material to the Phys Material Override slot in the Bouncy Ball actor
  7. Place the Bouncy Ball Actor high above the Floor in the level
  8. Position the camera so you can see both the floor and the Bouncy Ball
  9. Play In Editor at Current Camera Location
  10. Observe the Bouncy Ball

Expected Results:
Every time the Bouncy Ball Actor would bounce from hitting the Floor "Hello" would be printed.

Actual Results:
Some times the Bouncy Ball Actor prints "Hello" when hitting the floor.

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ComponentUE - Simulation - Physics
Affects Versions5.0
Target Fix5.0
Fix Commit18615358
Main Commit18615368
Release Commit18615358
CreatedDec 9, 2021
ResolvedJan 14, 2022
UpdatedJan 26, 2023