Fsx not connecting to self managed domain

Hi, I'm having a problem joining an fsx to my on site domain. I have a vpc and vpn setup and an ec2 instance that joined the domian but when I try to get the fsx to join it it can't reach the DNS servers I specified. Any help is appreciated. I ran a connection test from the EC2 instance and got all good results.

PS C:\Windows\system32> $result.tcpdetails

Port Result Description

88 Listening Kerberos authentication 135 Listening DCE / EPMAP (End Point Mapper) 389 Listening Lightweight Directory Access Protocol (LDAP) 445 Listening Directory Services SMB file sharing 464 Listening Kerberos Change/Set password 636 Listening Lightweight Directory Access Protocol over TLS/SSL (LDAPS) 3268 Listening Microsoft Global Catalog 3269 Listening Microsoft Global Catalog over SSL 9389 Listening Microsoft AD DS Web Services, PowerShell

Any help or suggestions are appreciated. Thanks