Thank you for your post.
Check to see if the server has two NIC's (Network Interface Card/Controller). If so, disable one and redeploy and/or reinstall.
Most importantly, FileMaker Server is not supported to run on Windows 8.1; only Windows Server 2008 and Windows Server 2012. Please review the System Requirements for FileMaker Server 14 via Knowledge Base Article 14401 at:
So. Now I have a good question:
It is not uncommon on physical servers to have several network adapters and not necessarily aggregated.
Do you think is it normal that we cannot choose the network card to map from FMS?
N.B .: Originally I installed FMS in a virtual Windows 2008 server (VMWare ESXi) with a dedicated NIC. But it is to expensive to leave the server run 24/7 only for FMS. It's the reason why I installed FMS on W8.1. But it runs well, for the moment, and it is the same core system that W2012. Isn't it?