Problems with conquering the Naxos and Paros islands

[all i do is clutch]

This is my third time siding with the Spartans to battle for control of Naxos and Paros, but when I win (and I always fully complete the conquest battle in my favor), the power just goes right back to the Athenians and they regain leadership to the point where they are fortified. The first few times I was just like "okay whatever I'll try again", but now I'm really annoyed with it. Have I missed something that states the Naxos and Paros Islands permanently belong to the Athenians? Or is this an actual issue with the game? Thanks

[UbiBaron]

Thanks for reporting this to us.

Have you completed the game story? I believe that the leader is an important part of the story and may be related to that.

To help us look into this, please create a case through the site here[support.ubi.com]

In this please include a copy of the save file, which you can find via the steps here[support.ubi.com]

When you have done that please provide us with the Case ID in this thread.

- Ubisoft Support