Can connect to Jellyfin remotely fine when I go to connect locally it won't work why?

Makes no sense.

Do I need to use the local ip instead to connect to the server locally ?

If it works remotely, it really should allow you to use that locally too. I can’t say I’ve heard of anything like this before.

Are you using an app? The browser?
What happens if you try the remote address, while local, using the browser?

In most cases, yes. Most domestic grade routers won’t perform NAT reflection, meaning a request from within your network for connection to your public IP will be sent out into the internet (and will evaporate at your ISP’s border routers).