Server offline with new computer

Not sure if this is the right section but need some help please.

I often Play missions with a pal.

I have an existing older computer and regularly for last few years set up a server on line and he joins me using the ip method.

Have built a new computer which is working fine DCS all downloaded all good. It is win 10 1903.

For the first time tried to set up on the new computer a server for my pal to join but keep getting server off line.

As a test tried to set up with my older computer through same router (wireless connection) and works fine.

The new computer through (wireless connection) to same router keeps saying server off line.

I have checked the windows fire wall on the new computer and the DCS exe for public and private is checked just as the old computer

Also the DCS is up to date on all machines.

Both computers win 10 only difference is one computer is 1903 and the other is 1809. The older computer has a plug in wireless usb and the new has an on board wireless , which seems to work fine.

Router has correct port pass throughs as same router works with older computer

Any ideas as to where I should look for the solution please

Thanks

Sorted this out. It was through my own oversight. I only record it in case anybody makes the same mistake. I built the new computer and now are using both the old and new. The new obviously for DCS. My problem was the port forwarding was still related to the old computer device. To solve my problem had to update the port forwarding in the router to the new computer device.

Obvious now!