Originally posted by B Rich:

But alas, my local LAN IP won't work for the server no matter what I do. Only the invite code or online IP work.

LAN IP vs. invite code / external is a crossplay/playfab problem.
Just disable crossplay on the dedicated server on your local LAN IP will work fine (with firewall exceptions of course).

Originally posted by B Rich:

Nor will my world load into the dedicated server. Its a new world every time no matter what I try.

Dunno what you're doing wrong with the world there. It couldn't be easier to just copy your world.db/.dwl to the proper server folder and tell the server startup (script) to use that world name. Done.
And "new world every time"? Are you running the server in a (windows) guest user account or something? That's the only reason I could think of right now for that behavior

Originally posted by B Rich:

Spent a whole day on it, and I do understand PCs...

So our only option is to pay for a server to play the same world in the same house?
That is pretty lame.

Sorry to disagree with you there but you don't seem to understand PCs - at least not to any degree I'd count...
I get not knowing about that stupid crossplay/playfab behavior but not even trying to disable an optional networking feature?...
Not to mention whatever problem you're having with your world (at least not without a lot more information).