There are so many variables to this its almost impossible to troubleshoot. Depends on the device your connecting from, your network setup, router, etc etc.

At minimum you need a device that can address.local hostnames...most linux Mac/iOS, and android devices do this by default, windows I know you need to install a third party app.

Im looking at some sort of zero-configuration solution to this that will work almost anywhere, without needing to find IPs etc for a future update.