How to reproduce:

1. Open the attached repro project "Case 820991.zip" and the only scene in it.
2. Play the scene and notice the character can not jump while running unless he reaches middle of the ground object.
3. Exit play mode and duplicate two "Piso" game objects in the Hierarchy window.
4. Delete the old ones "Piso" game objects and play the scene again.
5. Observe now player can jump while running.
6. Try to save the project, exit and open it - the bug will be reproducible again.

Expected behavior: Character can jump while running all the time.
Actual behavior: No force added to the character at a specific ground object position while using Rigidbody2D.AddForce.

Reproducible: 5.5.0a5, 5.4.0p1, 5.3.6p2, 5.2.4f1.