Welcome! You are going to need to provide more details, though, this sounds like this isn’t really Ionic related but instead a server configuration issue. Deploying an Ionic app on a server as a SPA or PWA is pretty much like any other SPA/PWA.
What is the “local server”? What is the “cell phone” - Android or iOS? What browser?
I know Chrome defaults to https as it is 2025 and every site should be using it 
It would be good practice to use a domain name and not the IP directly too.