Hello Eli Calkins,
Welcome to Microsoft Q&A forum.
May I know if the AI assistant suggestion works for you? I'm quite interested in what it says when you try to connect directly using IP rather than the name.
Since your server is quite old, and Windows 11 might have stricter SMB security than older server can support itself, this could also cause the issue. Additionally, I see that the server using SMB 1.0, which is disabled by default on Windows 11, so please follow the AI instruction to enable it and let me know.
Please let me know the results and whether they help.
I'm waiting for your reply.