why do people say "in-built" when it's not grammatically correct at all? It's "built-in" Unless you say inward-built "in-built" isn't even a thing. If you say it outright like "the port is built-in to the device" this is correct. Now use the same thing with in-built ", "the port is in-built to the device" see? makes no sense... if you ad "inward" it's better; "The port is inward-built on/to the device KINDA sounds better but still silly.
No idea where this came from but it'll never be grammatically correct in the English language.
"in-built" is simply incorrect usage and not even good slang much less proper.