NFS connection

Hello
After changing from the old router to the new one (MikroTik hap ac2) I have problems with my NFS Server.
My dedicated server cannot detect the nfs drive, I think the router is blocking it.
How can I fix it, I need nfs because i keep a lot of important data on it

We need more information,
Are your Servers on the same Network or seperated ?
How is your Router configured ? (We need export-File )