PPTP L2TP VPN disconnects immediately after connect. after several days I've found in latest windows 10 update, connection from windows 10 to mikrotik will be disconnected immediately after connection. I have no problem with other windows or OSes such as windows 7, MAC os, iOS. I've updated the router to the latest long term and then stable version and no luck. I don't have this problem on windows 10 with my other vpn servers which are technologies other than mikrotik.
After disabling Masquerade NAT for VPN users problem solved. but in this case, internet of users will be disconnected upon VPN connection.