Well there are a number of ways to combat this, you could try to set it up so that a motion sensor on the hallway checks to see if there was motion inactive for a minute in the bathroom when it trips and if so then turn off the light.
You could add a button to turn it off ( know not automatic )
You could increase it only to two minutes, and see if that works
And you would be looking to Increase sensitivity? It doesn’t look like the stock motion sensor has the capability to be altered: