It could not have come at most inopportune time. Its election period. And there are reelectionist senaotrs. Sen Pimentel is in a hurry because he will no longer part of the impeachment court he being a candidate for congressman at Marikina.
Senators are wary of the Sara factor, ie that she could have been the reason why PBBM got elected (he was beaten by Robredo in VP race, and even at recount) and voters sentiment could be pro Sara and some of them may lose.
So Senate leadership may be stalling. Or if Sarah wins the impeachment, the outcome of the midterm elections could change