When using the scroll wheel to move, the user will gradually come to a stop when going forward and will increase in speed when moving backward. If the user moves forward using this method until they come to a stop, they will no longer be able to move in the viewport.
Regression: Yes, this worked in 4.21.2-4753647+++UE4+Release-4.21
Result: The movement will gradually slow and eventually will stop. The user will no longer be able to move within the view port (even when using the arrow keys)
Expected: The User would continue to move at a steady pace
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-73484 in the post.