Forward Ports from Router to Mikrotik > 192.168.1.15
Forward Port from Mikrotik to LAN Devices IP > 192.168.88.#
To test look on the mikrotik to see if, when you test from outside (e.g. ping.eu), the rule should be hit and your packets count should rise by 1.
If it does ensure that your device you are forwarding the port to is actually allowing the connection. (Try access it internally, from a different computer using the local IP and port)
I already tried that didnt work.
But at the end, the next day i found the solution in 5 minutes. It has to have a fixed IP address on the PC that i am forwarding to, and McAfee antivirus was blocking the connection.
Thanks again