repeated connections by PPTP (Winbox 2.9.7)

Hello. I work at the Ministry of emergency situations in Russia, region of Tver. We use program soft named Winbox. During connecting remote users by protocol PPTP (VPN) there are reflected repeated connections the same users in Winbox. Because of it remote arrangment (Voip, APLSL) work wrong. How we may avoid repeated connections by PPTP (VPN) in Winbox?

2.9.7 is veeeeeery old and unsupported, upgrade to the latest version