Sweat is salty water, so it’s different. It’s released more when your body is hot, not because it’s dry. You probably aren’t sweating in an air conditioned room and showers are typically hotter than room temperature, probably hot enough to make you sweat. I’m not sure why you think your sweat would turn off just because you’re wet. If that was the case, you wouldn’t have pooled sweat pouring off you on humid days