Oh I see the issue, I had disabled your Surface Test in Event_001 order to isolate the Shape operator issue, without realizing your Surface Test is moving your particle to the next event.
Shape animation does not survive between events (meaning a Shape operator must be present in every event where you want shape animation)...so your animation stops because your particle leaves the event with the Shape operator. The fix for that issue is simple: just instance your Shape operator into your other events, so they update the animation as well (Shift + ALT + drag).
As for the changing topology...no, it also changes when preview mode is disabled. See attached video.
Shape animation does not survive between events (meaning a Shape operator must be present in every event where you want shape animation)...so your animation stops because your particle leaves the event with the Shape operator. The fix for that issue is simple: just instance your Shape operator into your other events, so they update the animation as well (Shift + ALT + drag).
As for the changing topology...no, it also changes when preview mode is disabled. See attached video.