Altium telling me floating input pin
What else do you have on the EN_B net? If you don't commit to every symbol using Input/Output/Bidirectional settings, if you tie EN_B to some other port that has Passive or similar, that error will show up. It won't be a single-pin net, but a Passive pin connected to an Input pin will cause that error.

You can choose to go into Project Options and disable that specific ERC, but that carries its own set of risks if that is what you are depending on to catch errors.