Then you have a different problem. For example a network (configuration) problem.
You haven't entered both IP and Hostname by any chance? If Hostname is entered, it MUST be accessable, it will not fall back to IP.
Before and after pressing ok on a mount. You can see it automatically updates the mount options. But it can only do that if it can connect to the server.
I confirm that there is a network because the receiver is visible to the rest of the network. I confirm that the actions of both examples in the photos have been performed.
https://pasteboard.co/Kh1YCtR.jpg
https://pasteboard.co/Kh1YQ2n.jpg