Thanks Crowbar for your help.
Here’s the official reply I received from Plarium Support, in case anyone else encounters the same issue:
Player Support Team (Plarium Support Center | Strategy Games)
October 28, 2025 – 15:56 EET
Hello!
Thank you for getting in touch.
It seems that your main account is located on the Facebook – Pirate Bay server.
Unfortunately, for technical reasons, it’s impossible to create a new account on a Facebook server or to transfer your progress to Facebook servers. Therefore, you won’t be able to access your main account from the new one you created on the Plarium International server.
If you have any further questions, please don’t hesitate to contact us at any time.
Kind regards,
Yurii
Player Support Team
Hope this helps anyone who runs into the same problem.