Removing floating gray icon

I am not sure which floating icon you are referring to. WIsh that you had provided a better description or a screen shot.

For now, I will have to assume that you are referring to the Assistive Touch icon. If you are referring to this icon, then open Settings ➡️ Accessibility ➡️ Touch ➡️ AssistiveTouch: Set this to OFF.

Axel F.

The gray floating icon on your screen might be AssistiveTouch. You can disable AssistiveTouch by going to Settings > Accessibility > Touch > AssistiveTouch, and turning the feature off.

Use AssistiveTouch on your iPhone, iPad, or iPod touch - Apple Support

Perhaps you could post a screenshot so that people could understand what you are referring to.