I have a 192.168.0.0/22 network set up, I also have a PPTP connection I use to work on their stuff remotely, however I can’t access anything on 192.168.1.x or 192.168.2.x or 192.168.3.x. I’m trying to work on their phone system which is on 192.168.1.25, can’t ping from my machine.
It is time to get a PPTP user connected and unable to access hosts on the LAN then run /system sup-output on your mikrotik and e-mail support@mikrotik.com. It works for me in the configuration you have described up through RouterOS 6.18.