Mikrotik remove all users when interface link down (RB750GL v6.46.1)

Why mikrotik remove all active users when interface link down? (RB750GL v6.46.1)

/log print
Jan/15/2020 01:31:02 interface,info out link down
Jan/15/2020 01:31:02 hotspot,info,debug user1 (10.0.0.18): logged out: host removed: iface removed