mute & hold while on call

With every call I make, I keep putting the person on the other line either on hold or mute. Obviously my face touches the screen and that what is causing it, but why is the screen so sensitive? Never had this issue with my Samsung, but I am stuck with my Huaweii now and really need to fix it. I tried to Google how to change sensitivity settings, but it seems the menu has changed on the Nova 5T from other Huaweii’s