Will a float installed backwards cause fuel gauge to be erratic or just misreading?

Hello,

If the float is not making proper connection with the resistor panel it will cause it to give erratic reading on the gauge.
The float goes just one way into the pump. If it is backwards, it will not fit or attach.

https://www.2carpros.com/articles/how-to-replace-an-electric-fuel-pump

See attached picture for your reference.

Let me know of any questions.
Thank you.