Toggling the Pivot Offset module in a Cascade Particle System has no effect on the particle system's position.
Tested in 4.20.3 (CL - 4369336), 4.21.2 (CL - 4753647), 4.22 (CL - 5439949), 4.23 (CL - 5501347)
Expected: The position of the particle system would reset
Result: The offset position remains the same
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-71905 in the post.