Upon the entry of a stop order under any part of RCW 19.100.120, the director shall promptly notify the applicant that the order has been entered and that the reasons therefor and that within fifteen days after receipt of a written request, the matter will be set down for hearing. If no hearing is requested within twenty calendar days and none is ordered by the director, the director shall enter his or her written findings of fact and conclusions of law and the order will remain in effect until it is modified or vacated by the director. If a hearing is requested or ordered, the director after notice of an opportunity for hearings to the issuer and to the applicant or registrant shall enter his or her written findings of fact and conclusions of law and may modify or vacate the order. The director may modify or vacate a stop order if he or she finds that the conditions which prompted his or her entry have changed or that it is otherwise in the public interest to do so.