An error occurred Sorry, Infuse encountered an error while trying to connect

Set up my Macbook and iPhone following these two guides (triple-checked every step to ensure I completed everything accurately).

Enabling File Sharing (Mac)

Streaming From a Mac, PC, or NAS

but when I add SMB to my iPhone (address, user & pass are all correct) and tap on add, it takes a good 2 minutes, and then gives me this error:

An error occurred
Sorry, Infuse encountered an error while trying to connect.

I tested it on two different iPhones (13 & SE). The result is the same.