To assist you in the best possible manner, I kindly ask that you please provide me screenshots that illustrate the problem to the Private Content area, this will allow me to thoroughly investigate and address your concerns more efficiently.
You are using Product Data Tabs widget, which is part of Elementor Pro plugin, please edit layout via Elementor https://prnt.sc/d9i4kfOtk1yv > select that widget and set font-size to 0 in Heading section https://prnt.sc/mzjAOG5RmWak